diff --git a/services/brig/src/Brig/API/Client.hs b/services/brig/src/Brig/API/Client.hs
index 46371c9329..5744bb9b95 100644
--- a/services/brig/src/Brig/API/Client.hs
+++ b/services/brig/src/Brig/API/Client.hs
@@ -145,9 +145,9 @@ addClientWithReAuthPolicy ::
   NewClient ->
   ExceptT ClientError (AppT r) Client
 addClientWithReAuthPolicy policy u con ip new = do
-  acc <- lift (wrapClient $ Data.lookupAccount u) >>= maybe (throwE (ClientUserNotFound u)) return
+  acc <- lift (wrapClient $ Data.lookupAccount u) >>= maybe (throwE (ClientUserNotFound u)) pure
   wrapHttpClientE $ verifyCode (newClientVerificationCode new) (userId . accountUser $ acc)
-  loc <- maybe (return Nothing) locationOf ip
+  loc <- maybe (pure Nothing) locationOf ip
   maxPermClients <- fromMaybe Opt.defUserMaxPermClients . Opt.setUserMaxPermClients <$> view settings
   let caps :: Maybe (Set ClientCapability)
       caps = updlhdev $ newClientCapabilities new
@@ -172,7 +172,7 @@ addClientWithReAuthPolicy policy u con ip new = do
       for_ (userEmail usr) $
         \email ->
           sendNewClientEmail (userDisplayName usr) email clt (userLocale usr)
-  return clt
+  pure clt
   where
     clientId' = clientIdFromPrekey (unpackLastPrekey $ newClientLastKey new)
 
@@ -374,7 +374,7 @@ claimLocalMultiPrekeyBundles protectee userClients = do
     getClientKeys u c = do
       key <- fmap prekeyData <$> Data.claimPrekey u c
       when (isNothing key) $ noPrekeys u c
-      return key
+      pure key
 
 -- Utilities
 
diff --git a/services/brig/src/Brig/API/Connection.hs b/services/brig/src/Brig/API/Connection.hs
index 21c1efcc35..da4a3dd5fc 100644
--- a/services/brig/src/Brig/API/Connection.hs
+++ b/services/brig/src/Brig/API/Connection.hs
@@ -122,15 +122,15 @@ createConnectionToLocalUser self conn target = do
           <$> wrapClient (Data.lookupName (tUnqualified self))
       let e2s = ConnectionUpdated s2o' (ucStatus <$> s2o) Nothing
       mapM_ (Intra.onConnectionEvent (tUnqualified self) (Just conn)) [e2o, e2s]
-      return s2o'
+      pure s2o'
 
     update :: UserConnection -> UserConnection -> ExceptT ConnectionError (AppT r) (ResponseForExistedCreated UserConnection)
     update s2o o2s = case (ucStatus s2o, ucStatus o2s) of
       (MissingLegalholdConsent, _) -> throwE $ InvalidTransition (tUnqualified self)
       (_, MissingLegalholdConsent) -> throwE $ InvalidTransition (tUnqualified self)
-      (Accepted, Accepted) -> return $ Existed s2o
-      (Accepted, Blocked) -> return $ Existed s2o
-      (Sent, Blocked) -> return $ Existed s2o
+      (Accepted, Accepted) -> pure $ Existed s2o
+      (Accepted, Blocked) -> pure $ Existed s2o
+      (Sent, Blocked) -> pure $ Existed s2o
       (Blocked, _) -> throwE $ InvalidTransition (tUnqualified self)
       (_, Blocked) -> change s2o SentWithHistory
       (_, Sent) -> accept s2o o2s
@@ -159,7 +159,7 @@ createConnectionToLocalUser self conn target = do
             <$> Data.lookupName (tUnqualified self)
       let e2s = ConnectionUpdated s2o' (Just $ ucStatus s2o) Nothing
       lift $ mapM_ (Intra.onConnectionEvent (tUnqualified self) (Just conn)) [e2o, e2s]
-      return $ Existed s2o'
+      pure $ Existed s2o'
 
     resend :: UserConnection -> UserConnection -> ExceptT ConnectionError (AppT r) (ResponseForExistedCreated UserConnection)
     resend s2o o2s = do
@@ -169,7 +169,7 @@ createConnectionToLocalUser self conn target = do
         logLocalConnection (tUnqualified self) (qUnqualified (ucTo s2o))
           . msg (val "Resending connection request")
       s2o' <- insert (Just s2o) (Just o2s)
-      return $ Existed s2o'
+      pure $ Existed s2o'
 
     change :: UserConnection -> RelationWithHistory -> ExceptT ConnectionError (AppT r) (ResponseForExistedCreated UserConnection)
     change c s = Existed <$> lift (wrapClient $ Data.updateConnection c s)
@@ -183,7 +183,7 @@ checkLegalholdPolicyConflict uid1 uid2 = do
   let catchProfileNotFound =
         -- Does not fit into 'ExceptT', so throw in '(AppT r)'.  Anyway at the time of writing
         -- this, users are guaranteed to exist when called from 'createConnectionToLocalUser'.
-        maybe (throwM (errorToWai @'E.UserNotFound)) return
+        maybe (throwM (errorToWai @'E.UserNotFound)) pure
 
   status1 <- lift (wrapHttpClient $ getLegalHoldStatus uid1) >>= catchProfileNotFound
   status2 <- lift (wrapHttpClient $ getLegalHoldStatus uid2) >>= catchProfileNotFound
@@ -270,14 +270,14 @@ updateConnectionToLocalUser self other newStatus conn = do
     -- Cancelled -> {Blocked}
     (Cancelled, _, Blocked) -> block s2o
     -- no change
-    (old, _, new) | old == new -> return Nothing
+    (old, _, new) | old == new -> pure Nothing
     -- invalid
     _ -> throwE $ InvalidTransition (tUnqualified self)
   let s2oUserConn = s2o'
   lift . for_ s2oUserConn $ \c ->
     let e2s = ConnectionUpdated c (Just $ ucStatus s2o) Nothing
      in Intra.onConnectionEvent (tUnqualified self) conn e2s
-  return s2oUserConn
+  pure s2oUserConn
   where
     accept :: UserConnection -> UserConnection -> ExceptT ConnectionError (AppT r) (Maybe UserConnection)
     accept s2o o2s = do
@@ -496,4 +496,4 @@ lookupConnections :: UserId -> Maybe UserId -> Range 1 500 Int32 -> (AppT r) Use
 lookupConnections from start size = do
   lusr <- qualifyLocal from
   rs <- wrapClient $ Data.lookupLocalConnections lusr start size
-  return $! UserConnectionList (Data.resultList rs) (Data.resultHasMore rs)
+  pure $! UserConnectionList (Data.resultList rs) (Data.resultHasMore rs)
diff --git a/services/brig/src/Brig/API/Handler.hs b/services/brig/src/Brig/API/Handler.hs
index 4d5e42b5d1..f845156e22 100644
--- a/services/brig/src/Brig/API/Handler.hs
+++ b/services/brig/src/Brig/API/Handler.hs
@@ -83,7 +83,7 @@ runHandler e r h k = do
   a <-
     runAppT e' (runExceptT h)
       `catches` brigErrorHandlers (view applog e) (unRequestId (view requestId e))
-  either (onError (view applog e') r k) return a
+  either (onError (view applog e') r k) pure a
 
 toServantHandler :: Env -> (Handler BrigCanonicalEffects) a -> Servant.Handler a
 toServantHandler env action = do
diff --git a/services/brig/src/Brig/API/Internal.hs b/services/brig/src/Brig/API/Internal.hs
index 8e0e1a1274..2b0c659aba 100644
--- a/services/brig/src/Brig/API/Internal.hs
+++ b/services/brig/src/Brig/API/Internal.hs
@@ -190,8 +190,8 @@ sitemap ::
   Members '[CodeStore, PasswordResetStore] r =>
   Routes a (Handler r) ()
 sitemap = do
-  get "/i/status" (continue $ const $ return empty) true
-  head "/i/status" (continue $ const $ return empty) true
+  get "/i/status" (continue $ const $ pure empty) true
+  head "/i/status" (continue $ const $ pure empty) true
 
   -- internal email activation (used in tests and in spar for validating emails obtained as
   -- SAML user identifiers).  if the validate query parameter is false or missing, only set
@@ -367,12 +367,12 @@ legalHoldClientRequestedH :: UserId ::: JsonRequest LegalHoldClientRequest ::: J
 legalHoldClientRequestedH (targetUser ::: req ::: _) = do
   clientRequest <- parseJsonBody req
   lift $ API.legalHoldClientRequested targetUser clientRequest
-  return $ setStatus status200 empty
+  pure $ setStatus status200 empty
 
 removeLegalHoldClientH :: UserId ::: JSON -> (Handler r) Response
 removeLegalHoldClientH (uid ::: _) = do
   lift $ API.removeLegalHoldClient uid
-  return $ setStatus status200 empty
+  pure $ setStatus status200 empty
 
 internalListClientsH :: JSON ::: JsonRequest UserSet -> (Handler r) Response
 internalListClientsH (_ ::: req) = do
@@ -481,7 +481,7 @@ getActivationCodeH (_ ::: emailOrPhone) = do
 getActivationCode :: Either Email Phone -> (Handler r) GetActivationCodeResp
 getActivationCode emailOrPhone = do
   apair <- lift . wrapClient $ API.lookupActivationCode emailOrPhone
-  maybe (throwStd activationKeyNotFound) (return . GetActivationCodeResp) apair
+  maybe (throwStd activationKeyNotFound) (pure . GetActivationCodeResp) apair
 
 newtype GetActivationCodeResp = GetActivationCodeResp (ActivationKey, ActivationCode)
 
@@ -511,19 +511,19 @@ changeAccountStatusH :: UserId ::: JsonRequest AccountStatusUpdate -> (Handler r
 changeAccountStatusH (usr ::: req) = do
   status <- suStatus <$> parseJsonBody req
   wrapHttpClientE (API.changeSingleAccountStatus usr status) !>> accountStatusError
-  return empty
+  pure empty
 
 getAccountStatusH :: JSON ::: UserId -> (Handler r) Response
 getAccountStatusH (_ ::: usr) = do
   status <- lift $ wrapClient $ API.lookupStatus usr
-  return $ case status of
+  pure $ case status of
     Just s -> json $ AccountStatusResp s
     Nothing -> setStatus status404 empty
 
 getConnectionsStatusUnqualified :: ConnectionsStatusRequest -> Maybe Relation -> (Handler r) [ConnectionStatus]
 getConnectionsStatusUnqualified ConnectionsStatusRequest {csrFrom, csrTo} flt = lift $ do
   r <- wrapClient $ maybe (API.lookupConnectionStatus' csrFrom) (API.lookupConnectionStatus csrFrom) csrTo
-  return $ maybe r (filterByRelation r) flt
+  pure $ maybe r (filterByRelation r) flt
   where
     filterByRelation l rel = filter ((== rel) . csStatus) l
 
@@ -547,35 +547,35 @@ getConnectionsStatus (ConnectionsStatusRequestV2 froms mtos mrel) = do
 revokeIdentityH :: Either Email Phone -> (Handler r) Response
 revokeIdentityH emailOrPhone = do
   lift $ API.revokeIdentity emailOrPhone
-  return $ setStatus status200 empty
+  pure $ setStatus status200 empty
 
 updateConnectionInternalH :: JSON ::: JsonRequest UpdateConnectionsInternal -> (Handler r) Response
 updateConnectionInternalH (_ ::: req) = do
   updateConn <- parseJsonBody req
   API.updateConnectionInternal updateConn !>> connError
-  return $ setStatus status200 empty
+  pure $ setStatus status200 empty
 
 checkBlacklistH :: Either Email Phone -> (Handler r) Response
 checkBlacklistH emailOrPhone = do
   bl <- lift $ API.isBlacklisted emailOrPhone
-  return $ setStatus (bool status404 status200 bl) empty
+  pure $ setStatus (bool status404 status200 bl) empty
 
 deleteFromBlacklistH :: Either Email Phone -> (Handler r) Response
 deleteFromBlacklistH emailOrPhone = do
   void . lift $ API.blacklistDelete emailOrPhone
-  return empty
+  pure empty
 
 addBlacklistH :: Either Email Phone -> (Handler r) Response
 addBlacklistH emailOrPhone = do
   void . lift $ API.blacklistInsert emailOrPhone
-  return empty
+  pure empty
 
 -- | Get any matching prefixes. Also try for shorter prefix matches,
 -- i.e. checking for +123456 also checks for +12345, +1234, ...
 getPhonePrefixesH :: PhonePrefix -> (Handler r) Response
 getPhonePrefixesH prefix = do
   results <- lift $ API.phonePrefixGet prefix
-  return $ case results of
+  pure $ case results of
     [] -> setStatus status404 empty
     _ -> json results
 
@@ -583,13 +583,13 @@ getPhonePrefixesH prefix = do
 deleteFromPhonePrefixH :: PhonePrefix -> (Handler r) Response
 deleteFromPhonePrefixH prefix = do
   void . lift $ API.phonePrefixDelete prefix
-  return empty
+  pure empty
 
 addPhonePrefixH :: JSON ::: JsonRequest ExcludedPrefix -> (Handler r) Response
 addPhonePrefixH (_ ::: req) = do
   prefix :: ExcludedPrefix <- parseJsonBody req
   void . lift $ API.phonePrefixInsert prefix
-  return empty
+  pure empty
 
 updateSSOIdH :: UserId ::: JSON ::: JsonRequest UserSSOId -> (Handler r) Response
 updateSSOIdH (uid ::: _ ::: req) = do
@@ -598,8 +598,8 @@ updateSSOIdH (uid ::: _ ::: req) = do
   if success
     then do
       lift $ wrapHttpClient $ Intra.onUserEvent uid Nothing (UserUpdated ((emptyUserUpdatedData uid) {eupSSOId = Just ssoid}))
-      return empty
-    else return . setStatus status404 $ plain "User does not exist or has no team."
+      pure empty
+    else pure . setStatus status404 $ plain "User does not exist or has no team."
 
 deleteSSOIdH :: UserId ::: JSON -> (Handler r) Response
 deleteSSOIdH (uid ::: _) = do
@@ -607,14 +607,14 @@ deleteSSOIdH (uid ::: _) = do
   if success
     then do
       lift $ wrapHttpClient $ Intra.onUserEvent uid Nothing (UserUpdated ((emptyUserUpdatedData uid) {eupSSOIdRemoved = True}))
-      return empty
-    else return . setStatus status404 $ plain "User does not exist or has no team."
+      pure empty
+    else pure . setStatus status404 $ plain "User does not exist or has no team."
 
 updateManagedByH :: UserId ::: JSON ::: JsonRequest ManagedByUpdate -> (Handler r) Response
 updateManagedByH (uid ::: _ ::: req) = do
   ManagedByUpdate managedBy <- parseJsonBody req
   lift $ wrapClient $ Data.updateManagedBy uid managedBy
-  return empty
+  pure empty
 
 updateRichInfoH :: UserId ::: JSON ::: JsonRequest RichInfoUpdate -> (Handler r) Response
 updateRichInfoH (uid ::: _ ::: req) = do
@@ -677,9 +677,9 @@ checkHandleInternalH =
 getContactListH :: JSON ::: UserId -> (Handler r) Response
 getContactListH (_ ::: uid) = do
   contacts <- lift . wrapClient $ API.lookupContactList uid
-  return $ json $ UserIds contacts
+  pure $ json $ UserIds contacts
 
 -- Utilities
 
 ifNothing :: Utilities.Error -> Maybe a -> (Handler r) a
-ifNothing e = maybe (throwStd e) return
+ifNothing e = maybe (throwStd e) pure
diff --git a/services/brig/src/Brig/API/MLS/KeyPackages/Validation.hs b/services/brig/src/Brig/API/MLS/KeyPackages/Validation.hs
index 7cdce75572..c76bb89190 100644
--- a/services/brig/src/Brig/API/MLS/KeyPackages/Validation.hs
+++ b/services/brig/src/Brig/API/MLS/KeyPackages/Validation.hs
@@ -111,7 +111,7 @@ checkRequiredExtensions re =
     <*> maybe (Left "Missing capability extension") (pure . Identity) (reCapabilities re)
 
 findExtensions :: [Extension] -> Either Text (RequiredExtensions Identity)
-findExtensions = (checkRequiredExtensions =<<) . getAp . foldMap findExtension
+findExtensions = checkRequiredExtensions <=< (getAp . foldMap findExtension)
 
 findExtension :: Extension -> Ap (Either Text) (RequiredExtensions Maybe)
 findExtension ext = (Ap (decodeExtension ext) >>=) . foldMap $ \case
diff --git a/services/brig/src/Brig/API/Public.hs b/services/brig/src/Brig/API/Public.hs
index 88efa357e9..ed52f76273 100644
--- a/services/brig/src/Brig/API/Public.hs
+++ b/services/brig/src/Brig/API/Public.hs
@@ -507,7 +507,7 @@ listPropertyKeys u = lift $ wrapClient (API.lookupPropertyKeys u)
 listPropertyKeysAndValues :: UserId -> Handler r Public.PropertyKeysAndValues
 listPropertyKeysAndValues u = do
   keysAndVals <- fmap Map.fromList . lift $ wrapClient (API.lookupPropertyKeysAndValues u)
-  fmap Public.PropertyKeysAndValues $ traverse parseStoredPropertyValue keysAndVals
+  Public.PropertyKeysAndValues <$> traverse parseStoredPropertyValue keysAndVals
 
 getPrekeyUnqualifiedH :: UserId -> UserId -> ClientId -> (Handler r) Public.ClientPrekey
 getPrekeyUnqualifiedH zusr user client = do
@@ -689,7 +689,7 @@ createUser (Public.NewUserPublic new) = lift . runExceptT $ do
     -- NOTE: Welcome e-mails for the team creator are not dealt by brig anymore
     sendWelcomeEmail e (CreateUserTeam t n) newUser l = case newUser of
       Public.NewTeamCreator _ ->
-        return ()
+        pure ()
       Public.NewTeamMember _ ->
         Team.sendMemberWelcomeMail e t n l
       Public.NewTeamMemberSSO _ ->
@@ -798,7 +798,7 @@ checkHandlesH (_ ::: _ ::: req) = do
   Public.CheckHandles hs num <- parseJsonBody req
   let handles = mapMaybe parseHandle (fromRange hs)
   free <- lift . wrapClient $ API.checkHandles handles (fromRange num)
-  return $ json (free :: [Handle])
+  pure $ json (free :: [Handle])
 
 -- | This endpoint returns UserHandleInfo instead of UserProfile for backwards
 -- compatibility, whereas the corresponding qualified endpoint (implemented by
@@ -841,7 +841,7 @@ completePasswordResetH ::
 completePasswordResetH (_ ::: req) = do
   Public.CompletePasswordReset {..} <- parseJsonBody req
   API.completePasswordReset cpwrIdent cpwrCode cpwrPassword !>> pwResetError
-  return empty
+  pure empty
 
 sendActivationCodeH :: JsonRequest Public.SendActivationCode -> (Handler r) Response
 sendActivationCodeH req =
@@ -891,7 +891,7 @@ updateConnection self conn other update = do
   let newStatus = Public.cuStatus update
   lself <- qualifyLocal self
   mc <- API.updateConnection lself other newStatus (Just conn) !>> connError
-  return $ maybe Public.Unchanged Public.Updated mc
+  pure $ maybe Public.Unchanged Public.Updated mc
 
 listLocalConnections :: UserId -> Maybe UserId -> Maybe (Range 1 500 Int32) -> (Handler r) Public.UserConnectionList
 listLocalConnections uid start msize = do
@@ -962,7 +962,7 @@ verifyDeleteUserH :: JsonRequest Public.VerifyDeleteUser ::: JSON -> (Handler r)
 verifyDeleteUserH (r ::: _) = do
   body <- parseJsonBody r
   API.verifyDeleteUser body !>> deleteUserError
-  return (setStatus status200 empty)
+  pure (setStatus status200 empty)
 
 updateUserEmail :: UserId -> UserId -> Public.EmailUpdate -> (Handler r) ()
 updateUserEmail zuserId emailOwnerId (Public.EmailUpdate email) = do
@@ -1015,10 +1015,10 @@ activate :: Public.Activate -> (Handler r) ActivationRespWithStatus
 activate (Public.Activate tgt code dryrun)
   | dryrun = do
     wrapClientE (API.preverify tgt code) !>> actError
-    return ActivationRespDryRun
+    pure ActivationRespDryRun
   | otherwise = do
     result <- API.activate tgt code Nothing !>> actError
-    return $ case result of
+    pure $ case result of
       ActivationSuccess ident x -> respond ident x
       ActivationPass -> ActivationRespPass
   where
@@ -1088,9 +1088,9 @@ deprecatedCompletePasswordResetH (_ ::: k ::: req) = do
     (Public.pwrCode pwr)
     (Public.pwrPassword pwr)
     !>> pwResetError
-  return empty
+  pure empty
 
 -- Utilities
 
 ifNothing :: Utilities.Error -> Maybe a -> (Handler r) a
-ifNothing e = maybe (throwStd e) return
+ifNothing e = maybe (throwStd e) pure
diff --git a/services/brig/src/Brig/API/User.hs b/services/brig/src/Brig/API/User.hs
index d68d696d92..592f4d62d0 100644
--- a/services/brig/src/Brig/API/User.hs
+++ b/services/brig/src/Brig/API/User.hs
@@ -299,7 +299,7 @@ createUser new = do
 
   lift $ initAccountFeatureConfig uid
 
-  return $! CreateUserResult account edata pdata createUserTeam
+  pure $! CreateUserResult account edata pdata createUserTeam
   where
     -- NOTE: all functions in the where block don't use any arguments of createUser
 
@@ -309,14 +309,14 @@ createUser new = do
       email <- for (newUserEmail newUser) $ \e ->
         either
           (const $ throwE RegisterErrorInvalidEmail)
-          return
+          pure
           (validateEmail e)
 
       -- Validate phone
       phone <- for (newUserPhone newUser) $ \p ->
         maybe
           (throwE RegisterErrorInvalidPhone)
-          return
+          pure
           =<< lift (wrapClient $ validatePhone p)
 
       for_ (catMaybes [userEmailKey <$> email, userPhoneKey <$> phone]) $ \k ->
@@ -334,7 +334,7 @@ createUser new = do
             (Just invite, Just em)
               | e == userEmailKey em -> do
                 _ <- ensureMemberCanJoin (Team.iiTeam ii)
-                return $ Just (invite, ii, Team.iiTeam ii)
+                pure $ Just (invite, ii, Team.iiTeam ii)
             _ -> throwE RegisterErrorInvalidInvitationCode
         Nothing -> throwE RegisterErrorInvalidInvitationCode
 
@@ -406,13 +406,13 @@ createUser new = do
             field "user" (toByteString uid)
               . field "activation.key" (toByteString $ activationKey edata)
               . msg (val "Created email activation key/code pair")
-          return $ Just edata
+          pure $ Just edata
         Just c -> do
           ak <- liftIO $ Data.mkActivationKey ek
           void $
             activateWithCurrency (ActivateKey ak) c (Just uid) (bnuCurrency =<< newTeam)
               !>> activationErrorToRegisterError
-          return Nothing
+          pure Nothing
 
     -- Handle phone activation (deprecated, see #RefRegistrationNoPreverification in /docs/reference/user/registration.md)
     handlePhoneActivation :: Maybe Phone -> UserId -> ExceptT RegisterError (AppT r) (Maybe Activation)
@@ -425,11 +425,11 @@ createUser new = do
             field "user" (toByteString uid)
               . field "activation.key" (toByteString $ activationKey pdata)
               . msg (val "Created phone activation key/code pair")
-          return $ Just pdata
+          pure $ Just pdata
         Just c -> do
           ak <- liftIO $ Data.mkActivationKey pk
           void $ activate (ActivateKey ak) c (Just uid) !>> activationErrorToRegisterError
-          return Nothing
+          pure Nothing
 
 initAccountFeatureConfig :: UserId -> (AppT r) ()
 initAccountFeatureConfig uid = do
@@ -462,7 +462,7 @@ createUserInviteViaScim uid (NewUserScimInvitation tid loc name rawEmail) = do
         True
   lift . wrapClient $ Data.insertAccount account Nothing Nothing activated
 
-  return account
+  pure account
 
 -- | docs/reference/user/registration.md {#RefRestrictRegistration}.
 checkRestrictedUserCreation :: NewUser -> ExceptT RegisterError (AppT r) ()
@@ -551,17 +551,17 @@ checkHandle uhandle = do
   if
       | isJust owner ->
         -- Handle is taken (=> getHandleInfo will return 200)
-        return CheckHandleFound
+        pure CheckHandleFound
       | isBlacklistedHandle xhandle ->
         -- Handle is free but cannot be taken
         --
         -- FUTUREWORK: i wonder if this is correct?  isn't this the error for malformed
         -- handles?  shouldn't we throw not-found here?  or should there be a fourth case
         -- 'CheckHandleBlacklisted'?
-        return CheckHandleInvalid
+        pure CheckHandleInvalid
       | otherwise ->
         -- Handle is free and can be taken
-        return CheckHandleNotFound
+        pure CheckHandleNotFound
 
 --------------------------------------------------------------------------------
 -- Check Handles
@@ -569,8 +569,8 @@ checkHandle uhandle = do
 checkHandles :: MonadClient m => [Handle] -> Word -> m [Handle]
 checkHandles check num = reverse <$> collectFree [] check num
   where
-    collectFree free _ 0 = return free
-    collectFree free [] _ = return free
+    collectFree free _ 0 = pure free
+    collectFree free [] _ = pure free
     collectFree free (h : hs) n =
       if isBlacklistedHandle h
         then collectFree free hs n
@@ -610,7 +610,7 @@ changeEmail u email allowScim = do
   em <-
     either
       (throwE . InvalidNewEmail email)
-      return
+      pure
       (validateEmail email)
   let ek = userEmailKey em
   blacklisted <- lift . wrapClient $ Blacklist.exists ek
@@ -620,10 +620,10 @@ changeEmail u email allowScim = do
   unless available $
     throwE $
       EmailExists email
-  usr <- maybe (throwM $ UserProfileNotFound u) return =<< lift (wrapClient $ Data.lookupUser WithPendingInvitations u)
+  usr <- maybe (throwM $ UserProfileNotFound u) pure =<< lift (wrapClient $ Data.lookupUser WithPendingInvitations u)
   case emailIdentity =<< userIdentity usr of
     -- The user already has an email address and the new one is exactly the same
-    Just current | current == em -> return ChangeEmailIdempotent
+    Just current | current == em -> pure ChangeEmailIdempotent
     _ -> do
       unless
         ( userManagedBy usr /= ManagedByScim
@@ -632,7 +632,7 @@ changeEmail u email allowScim = do
         $ throwE EmailManagedByScim
       timeout <- setActivationTimeout <$> view settings
       act <- lift . wrapClient $ Data.newActivation ek timeout (Just u)
-      return $ ChangeEmailNeedsActivation (usr, act, em)
+      pure $ ChangeEmailNeedsActivation (usr, act, em)
 
 -------------------------------------------------------------------------------
 -- Change Phone
@@ -642,7 +642,7 @@ changePhone u phone = do
   canonical <-
     maybe
       (throwE InvalidNewPhone)
-      return
+      pure
       =<< lift (wrapClient $ validatePhone phone)
   let pk = userPhoneKey canonical
   available <- lift . wrapClient $ Data.keyAvailable pk (Just u)
@@ -657,7 +657,7 @@ changePhone u phone = do
   when prefixExcluded $
     throwE BlacklistedNewPhone
   act <- lift . wrapClient $ Data.newActivation pk timeout (Just u)
-  return (act, canonical)
+  pure (act, canonical)
 
 -------------------------------------------------------------------------------
 -- Remove Email
@@ -699,7 +699,7 @@ revokeIdentity key = do
   let uk = either userEmailKey userPhoneKey key
   mu <- wrapClient $ Data.lookupKey uk
   case mu of
-    Nothing -> return ()
+    Nothing -> pure ()
     Just u ->
       fetchUserIdentity u >>= \case
         Just (FullIdentity _ _) -> revokeKey u uk
@@ -709,7 +709,7 @@ revokeIdentity key = do
         Just (PhoneIdentity p) | Right p == key -> do
           revokeKey u uk
           wrapClient $ Data.deactivateUser u
-        _ -> return ()
+        _ -> pure ()
   where
     revokeKey :: UserId -> UserKey -> AppT r ()
     revokeKey u uk = do
@@ -779,8 +779,8 @@ changeSingleAccountStatus uid status = do
 mkUserEvent :: (MonadUnliftIO m, Traversable t, MonadClient m) => t UserId -> AccountStatus -> ExceptT AccountStatusError m (UserId -> UserEvent)
 mkUserEvent usrs status =
   case status of
-    Active -> return UserResumed
-    Suspended -> lift $ mapConcurrently revokeAllCookies usrs >> return UserSuspended
+    Active -> pure UserResumed
+    Suspended -> lift $ mapConcurrently revokeAllCookies usrs >> pure UserSuspended
     Deleted -> throwE InvalidAccountStatus
     Ephemeral -> throwE InvalidAccountStatus
     PendingInvitation -> throwE InvalidAccountStatus
@@ -813,13 +813,13 @@ activateWithCurrency tgt code usr cur = do
       . msg (val "Activating")
   event <- wrapClientE $ Data.activateKey key code usr
   case event of
-    Nothing -> return ActivationPass
+    Nothing -> pure ActivationPass
     Just e -> do
       (uid, ident, first) <- lift $ onActivated e
       when first $
         lift $
           activateTeam uid
-      return $ ActivationSuccess ident first
+      pure $ ActivationSuccess ident first
   where
     activateTeam uid = do
       tid <- wrapHttp $ Intra.getTeamId uid
@@ -842,14 +842,14 @@ onActivated (AccountActivated account) = do
   Log.debug $ field "user" (toByteString uid) . field "action" (Log.val "User.onActivated")
   Log.info $ field "user" (toByteString uid) . msg (val "User activated")
   wrapHttpClient $ Intra.onUserEvent uid Nothing $ UserActivated (accountUser account)
-  return (uid, userIdentity (accountUser account), True)
+  pure (uid, userIdentity (accountUser account), True)
 onActivated (EmailActivated uid email) = do
   wrapHttpClient $ Intra.onUserEvent uid Nothing (emailUpdated uid email)
   wrapHttpClient $ Data.deleteEmailUnvalidated uid
-  return (uid, Just (EmailIdentity email), False)
+  pure (uid, Just (EmailIdentity email), False)
 onActivated (PhoneActivated uid phone) = do
   wrapHttpClient $ Intra.onUserEvent uid Nothing (phoneUpdated uid phone)
-  return (uid, Just (PhoneIdentity phone), False)
+  pure (uid, Just (PhoneIdentity phone), False)
 
 -- docs/reference/user/activation.md {#RefActivationRequest}
 sendActivationCode :: Either Email Phone -> Maybe Locale -> Bool -> ExceptT SendActivationCodeError (AppT r) ()
@@ -858,7 +858,7 @@ sendActivationCode emailOrPhone loc call = case emailOrPhone of
     ek <-
       either
         (const . throwE . InvalidRecipient $ userEmailKey email)
-        (return . userEmailKey)
+        (pure . userEmailKey)
         (validateEmail email)
     exists <- lift $ isJust <$> wrapClient (Data.lookupKey ek)
     when exists $
@@ -877,7 +877,7 @@ sendActivationCode emailOrPhone loc call = case emailOrPhone of
     canonical <-
       maybe
         (throwE $ InvalidRecipient (userPhoneKey phone))
-        return
+        pure
         =<< lift (wrapClient $ validatePhone phone)
     let pk = userPhoneKey canonical
     exists <- lift $ isJust <$> wrapClient (Data.lookupKey pk)
@@ -906,7 +906,7 @@ sendActivationCode emailOrPhone loc call = case emailOrPhone of
         Just c' -> liftIO $ (,c') <$> Data.mkActivationKey k
         Nothing -> lift $ do
           dat <- Data.newActivation k timeout u
-          return (activationKey dat, activationCode dat)
+          pure (activationKey dat, activationCode dat)
     sendVerificationEmail ek uc = do
       p <- wrapClientE $ mkPair ek uc Nothing
       void . forEmailKey ek $ \em ->
@@ -915,7 +915,7 @@ sendActivationCode emailOrPhone loc call = case emailOrPhone of
     sendActivationEmail ek uc uid = do
       -- FUTUREWORK(fisx): we allow for 'PendingInvitations' here, but I'm not sure this
       -- top-level function isn't another piece of a deprecated onboarding flow?
-      u <- maybe (notFound uid) return =<< lift (wrapClient $ Data.lookupUser WithPendingInvitations uid)
+      u <- maybe (notFound uid) pure =<< lift (wrapClient $ Data.lookupUser WithPendingInvitations uid)
       p <- wrapClientE $ mkPair ek (Just uc) (Just uid)
       let ident = userIdentity u
           name = userDisplayName u
@@ -935,19 +935,19 @@ sendActivationCode emailOrPhone loc call = case emailOrPhone of
             sendActivationMail em name p loc' ident
 
 mkActivationKey :: (MonadClient m, MonadReader Env m) => ActivationTarget -> ExceptT ActivationError m ActivationKey
-mkActivationKey (ActivateKey k) = return k
+mkActivationKey (ActivateKey k) = pure k
 mkActivationKey (ActivateEmail e) = do
   ek <-
     either
       (throwE . InvalidActivationEmail e)
-      (return . userEmailKey)
+      (pure . userEmailKey)
       (validateEmail e)
   liftIO $ Data.mkActivationKey ek
 mkActivationKey (ActivatePhone p) = do
   pk <-
     maybe
       (throwE $ InvalidActivationPhone p)
-      (return . userPhoneKey)
+      (pure . userPhoneKey)
       =<< lift (validatePhone p)
   liftIO $ Data.mkActivationKey pk
 
@@ -977,7 +977,7 @@ beginPasswordReset ::
   ExceptT PasswordResetError (AppT r) (UserId, PasswordResetPair)
 beginPasswordReset target = do
   let key = either userEmailKey userPhoneKey target
-  user <- lift (wrapClient $ Data.lookupKey key) >>= maybe (throwE InvalidPasswordResetKey) return
+  user <- lift (wrapClient $ Data.lookupKey key) >>= maybe (throwE InvalidPasswordResetKey) pure
   lift . Log.debug $ field "user" (toByteString user) . field "action" (Log.val "User.beginPasswordReset")
   status <- lift . wrapClient $ Data.lookupStatus user
   unless (status == Just Active) $
@@ -1020,7 +1020,7 @@ mkPasswordResetKey ::
   PasswordResetIdentity ->
   ExceptT PasswordResetError (AppT r) PasswordResetKey
 mkPasswordResetKey ident = case ident of
-  PasswordResetIdentityKey k -> return k
+  PasswordResetIdentityKey k -> pure k
   PasswordResetEmailIdentity e ->
     wrapClientE (user (userEmailKey e))
       >>= lift . liftSem . E.mkPasswordResetKey
@@ -1028,7 +1028,7 @@ mkPasswordResetKey ident = case ident of
     wrapClientE (user (userPhoneKey p))
       >>= lift . liftSem . E.mkPasswordResetKey
   where
-    user uk = lift (Data.lookupKey uk) >>= maybe (throwE InvalidPasswordResetKey) return
+    user uk = lift (Data.lookupKey uk) >>= maybe (throwE InvalidPasswordResetKey) pure
 
 -------------------------------------------------------------------------------
 -- User Deletion
@@ -1047,7 +1047,7 @@ deleteUser uid pwd = do
   case account of
     Nothing -> throwE DeleteUserInvalid
     Just a -> case accountStatus a of
-      Deleted -> return Nothing
+      Deleted -> pure Nothing
       Suspended -> ensureNotOwner a >> go a
       Active -> ensureNotOwner a >> go a
       Ephemeral -> go a
@@ -1072,7 +1072,7 @@ deleteUser uid pwd = do
       Just emailOrPhone -> sendCode a emailOrPhone
       Nothing -> case pwd of
         Just _ -> throwE DeleteUserMissingPassword
-        Nothing -> lift $ wrapHttpClient $ deleteAccount a >> return Nothing
+        Nothing -> lift $ wrapHttpClient $ deleteAccount a >> pure Nothing
     byPassword a pw = do
       lift . Log.info $
         field "user" (toByteString uid)
@@ -1083,7 +1083,7 @@ deleteUser uid pwd = do
         Just p -> do
           unless (verifyPassword pw p) $
             throwE DeleteUserInvalidPassword
-          lift $ wrapHttpClient $ deleteAccount a >> return Nothing
+          lift $ wrapHttpClient $ deleteAccount a >> pure Nothing
     sendCode a target = do
       gen <- Code.mkGen (either Code.ForEmail Code.ForPhone target)
       pending <- lift . wrapClient $ Code.lookup (Code.genKey gen) Code.AccountDeletion
@@ -1110,7 +1110,7 @@ deleteUser uid pwd = do
             (\p -> lift $ wrapClient $ sendDeletionSms p k v l)
             target
             `onException` wrapClientE (Code.delete k Code.AccountDeletion)
-          return $! Just $! Code.codeTTL c
+          pure $! Just $! Code.codeTTL c
 
 -- | Conclude validation and scheduling of user's deletion request that was initiated in
 -- 'deleteUser'.  Called via @post /delete@.
@@ -1119,7 +1119,7 @@ verifyDeleteUser d = do
   let key = verifyDeleteUserKey d
   let code = verifyDeleteUserCode d
   c <- lift . wrapClient $ Code.verify key Code.AccountDeletion code
-  a <- maybe (throwE DeleteUserInvalidCode) return (Code.codeAccount =<< c)
+  a <- maybe (throwE DeleteUserInvalidCode) pure (Code.codeAccount =<< c)
   account <- lift . wrapClient $ Data.lookupAccount (Id a)
   for_ account $ lift . wrapHttpClient . deleteAccount
   lift . wrapClient $ Code.delete key Code.AccountDeletion
@@ -1165,7 +1165,7 @@ deleteAccount account@(accountUser -> user) = do
   where
     mkTombstone = do
       defLoc <- setDefaultUserLocale <$> view settings
-      return $
+      pure $
         account
           { accountStatus = Deleted,
             accountUser =
@@ -1191,7 +1191,7 @@ lookupActivationCode emailOrPhone = do
   let uk = either userEmailKey userPhoneKey emailOrPhone
   k <- liftIO $ Data.mkActivationKey uk
   c <- fmap snd <$> Data.lookupActivationCode uk
-  return $ (k,) <$> c
+  pure $ (k,) <$> c
 
 lookupPasswordResetCode ::
   Members '[CodeStore, PasswordResetStore] r =>
@@ -1201,11 +1201,11 @@ lookupPasswordResetCode emailOrPhone = do
   let uk = either userEmailKey userPhoneKey emailOrPhone
   usr <- wrapClient $ Data.lookupKey uk
   liftSem $ case usr of
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
     Just u -> do
       k <- E.mkPasswordResetKey u
       c <- E.lookupPasswordResetCode u
-      return $ (k,) <$> c
+      pure $ (k,) <$> c
 
 deleteUserNoVerify ::
   ( MonadReader Env m,
@@ -1237,13 +1237,13 @@ userGC ::
   User ->
   m User
 userGC u = case userExpire u of
-  Nothing -> return u
+  Nothing -> pure u
   (Just (fromUTCTimeMillis -> e)) -> do
     now <- liftIO =<< view currentTime
     -- ephemeral users past their expiry date are deleted
     when (diffUTCTime e now < 0) $
       deleteUserNoVerify (userId u)
-    return u
+    pure u
 
 lookupProfile ::
   ( MonadClient m,
@@ -1344,7 +1344,7 @@ lookupLocalProfiles requestingUser others = do
       Nothing -> pure EmailVisibleToSelf'
     EmailVisibleToSelf -> pure EmailVisibleToSelf'
   usersAndStatus <- for users $ \u -> (u,) <$> getLegalHoldStatus' u
-  return $ map (toProfile emailVisibility'' css) usersAndStatus
+  pure $ map (toProfile emailVisibility'' css) usersAndStatus
   where
     toMap :: [ConnectionStatus] -> Map UserId Relation
     toMap = Map.fromList . map (csFrom &&& csStatus)
diff --git a/services/brig/src/Brig/API/Util.hs b/services/brig/src/Brig/API/Util.hs
index 92c3c4bffb..f7e068a29b 100644
--- a/services/brig/src/Brig/API/Util.hs
+++ b/services/brig/src/Brig/API/Util.hs
@@ -62,7 +62,7 @@ import Wire.API.User.Search (FederatedUserSearchPolicy (NoSearch))
 lookupProfilesMaybeFilterSameTeamOnly :: UserId -> [UserProfile] -> (Handler r) [UserProfile]
 lookupProfilesMaybeFilterSameTeamOnly self us = do
   selfTeam <- lift $ wrapClient $ Data.lookupUserTeam self
-  return $ case selfTeam of
+  pure $ case selfTeam of
     Just team -> filter (\x -> profileTeam x == Just team) us
     Nothing -> us
 
@@ -71,7 +71,7 @@ fetchUserIdentity uid =
   lookupSelfProfile uid
     >>= maybe
       (throwM $ UserProfileNotFound uid)
-      (return . userIdentity . selfUser)
+      (pure . userIdentity . selfUser)
 
 -- | Obtain a profile for a user as he can see himself.
 lookupSelfProfile :: UserId -> (AppT r) (Maybe SelfProfile)
@@ -80,7 +80,7 @@ lookupSelfProfile = fmap (fmap mk) . wrapClient . Data.lookupAccount
     mk a = SelfProfile (accountUser a)
 
 validateHandle :: Text -> (Handler r) Handle
-validateHandle = maybe (throwStd (errorToWai @'InvalidHandle)) return . parseHandle
+validateHandle = maybe (throwStd (errorToWai @'InvalidHandle)) pure . parseHandle
 
 logEmail :: Email -> (Msg -> Msg)
 logEmail email =
diff --git a/services/brig/src/Brig/AWS.hs b/services/brig/src/Brig/AWS.hs
index 294de9b578..85c081a514 100644
--- a/services/brig/src/Brig/AWS.hs
+++ b/services/brig/src/Brig/AWS.hs
@@ -114,9 +114,9 @@ mkEnv lgr opts emailOpts mgr = do
       sesEndpoint
       dynamoEndpoint
       (mkEndpoint SQS.defaultService (Opt.sqsEndpoint opts))
-  sq <- maybe (return Nothing) (fmap Just . getQueueUrl e . Opt.sesQueue) emailOpts
-  jq <- maybe (return Nothing) (fmap Just . getQueueUrl e) (Opt.userJournalQueue opts)
-  return (Env g sq jq pk e)
+  sq <- maybe (pure Nothing) (fmap Just . getQueueUrl e . Opt.sesQueue) emailOpts
+  jq <- maybe (pure Nothing) (fmap Just . getQueueUrl e) (Opt.userJournalQueue opts)
+  pure (Env g sq jq pk e)
   where
     mkEndpoint svc e = AWS.setEndpoint (e ^. awsSecure) (e ^. awsHost) (e ^. awsPort) svc
     mkAwsEnv g ses dyn sqs = do
@@ -180,7 +180,7 @@ listen throttleMillis url callback = forever . handleAny unexpectedError $ do
         & set SQS.receiveMessage_waitTimeSeconds (Just 20)
           . set SQS.receiveMessage_maxNumberOfMessages (Just 10)
     onMessage m =
-      case decodeStrict =<< Text.encodeUtf8 <$> m ^. SQS.message_body of
+      case decodeStrict . Text.encodeUtf8 =<< (m ^. SQS.message_body) of
         Nothing -> err $ msg ("Failed to parse SQS event: " ++ show m)
         Just n -> do
           debug $ msg ("Received SQS event: " ++ show n)
@@ -214,7 +214,7 @@ sendMail m = do
           & SES.sendRawEmail_destinations ?~ fmap addressEmail (mailTo m)
           & SES.sendRawEmail_source ?~ addressEmail (mailFrom m)
   resp <- retrying retry5x (const canRetry) $ const (sendCatch raw)
-  void $ either check return resp
+  void $ either check pure resp
   where
     check x = case x of
       -- To map rejected domain names by SES to 400 responses, in order
@@ -242,7 +242,7 @@ send :: AWSRequest r => r -> Amazon (AWSResponse r)
 send r = throwA =<< sendCatch r
 
 throwA :: Either AWS.Error a -> Amazon a
-throwA = either (throwM . GeneralError) return
+throwA = either (throwM . GeneralError) pure
 
 execCatch ::
   (AWSRequest a, MonadUnliftIO m, MonadCatch m, MonadThrow m, MonadIO m) =>
@@ -259,7 +259,7 @@ exec ::
   AWS.Env ->
   a ->
   m (AWSResponse a)
-exec e cmd = liftIO (execCatch e cmd) >>= either (throwM . GeneralError) return
+exec e cmd = liftIO (execCatch e cmd) >>= either (throwM . GeneralError) pure
 
 canRetry :: MonadIO m => Either AWS.Error a -> m Bool
 canRetry (Right _) = pure False
diff --git a/services/brig/src/Brig/AWS/Types.hs b/services/brig/src/Brig/AWS/Types.hs
index e30b38d61d..8847d66513 100644
--- a/services/brig/src/Brig/AWS/Types.hs
+++ b/services/brig/src/Brig/AWS/Types.hs
@@ -41,9 +41,9 @@ data SESBounceType
   deriving (Eq, Show)
 
 instance FromJSON SESBounceType where
-  parseJSON "Undetermined" = return BounceUndetermined
-  parseJSON "Permanent" = return BouncePermanent
-  parseJSON "Transient" = return BounceTransient
+  parseJSON "Undetermined" = pure BounceUndetermined
+  parseJSON "Permanent" = pure BouncePermanent
+  parseJSON "Transient" = pure BounceTransient
   parseJSON x = fail $ "Unknown type: " <> show x
 
 instance FromJSON SESNotification where
@@ -55,10 +55,10 @@ instance FromJSON SESNotification where
         bt <- b .: "bounceType"
         br <- b .: "bouncedRecipients"
         em <- mapM (\r -> r .: "emailAddress") br
-        return $! MailBounce bt em
+        pure $! MailBounce bt em
       "Complaint" -> do
         c <- o .: "complaint"
         cr <- c .: "complainedRecipients"
         em <- mapM (\r -> r .: "emailAddress") cr
-        return $! MailComplaint em
+        pure $! MailComplaint em
       x -> fail ("Brig.AWS: Unexpected notification type" ++ show x)
diff --git a/services/brig/src/Brig/App.hs b/services/brig/src/Brig/App.hs
index c7279183b4..80ba594971 100644
--- a/services/brig/src/Brig/App.hs
+++ b/services/brig/src/Brig/App.hs
@@ -242,7 +242,7 @@ newEnv o = do
     Just True -> Just <$> newMVar ()
     _ -> pure Nothing
   kpLock <- newMVar ()
-  return
+  pure
     $! Env
       { _cargohold = mkEndpoint $ Opt.cargohold o,
         _galley = mkEndpoint $ Opt.galley o,
@@ -279,17 +279,17 @@ newEnv o = do
         _keyPackageLocalLock = kpLock
       }
   where
-    emailConn _ (Opt.EmailAWS aws) = return (Just aws, Nothing)
+    emailConn _ (Opt.EmailAWS aws) = pure (Just aws, Nothing)
     emailConn lgr (Opt.EmailSMTP s) = do
       let host = Opt.smtpEndpoint s ^. epHost
           port = Just $ fromInteger $ toInteger $ Opt.smtpEndpoint s ^. epPort
       smtpCredentials <- case Opt.smtpCredentials s of
         Just (Opt.EmailSMTPCredentials u p) -> do
           pass <- initCredentials p
-          return $ Just (SMTP.Username u, SMTP.Password pass)
-        _ -> return Nothing
+          pure $ Just (SMTP.Username u, SMTP.Password pass)
+        _ -> pure Nothing
       smtp <- SMTP.initSMTP lgr host port smtpCredentials (Opt.smtpConnType s)
-      return (Nothing, Just smtp)
+      pure (Nothing, Just smtp)
     mkEndpoint service = RPC.host (encodeUtf8 (service ^. epHost)) . RPC.port (service ^. epPort) $ RPC.empty
 
 mkIndexEnv :: Opts -> Logger -> Manager -> Metrics -> Endpoint -> IndexEnv
@@ -302,12 +302,12 @@ mkIndexEnv o lgr mgr mtr galleyEndpoint =
    in IndexEnv mtr lgr' bhe Nothing mainIndex additionalIndex additionalBhe galleyEndpoint mgr
 
 geoSetup :: Logger -> FS.WatchManager -> Maybe FilePath -> IO (Maybe (IORef GeoIp.GeoDB))
-geoSetup _ _ Nothing = return Nothing
+geoSetup _ _ Nothing = pure Nothing
 geoSetup lgr w (Just db) = do
   path <- canonicalizePath db
   geodb <- newIORef =<< GeoIp.openGeoDB path
   startWatching w path (replaceGeoDb lgr geodb)
-  return $ Just geodb
+  pure $ Just geodb
 
 startWatching :: FS.WatchManager -> FilePath -> FS.Action -> IO ()
 startWatching w p = void . FS.watchDir w (Path.dropFileName p) predicate
@@ -384,7 +384,7 @@ initExtGetManager = do
           managerResponseTimeout = responseTimeoutMicro 10000000
         }
   Just sha <- getDigestByName "SHA256"
-  return (mgr, mkVerify sha)
+  pure (mgr, mkVerify sha)
   where
     mkVerify sha fprs =
       let pinset = map toByteString' fprs
@@ -411,12 +411,12 @@ initCassandra o g = do
         . Cas.setPolicy (Cas.dcFilterPolicyIfConfigured g (Opt.cassandra o ^. casFilterNodesByDatacentre))
         $ Cas.defSettings
   runClient p $ versionCheck schemaVersion
-  return p
+  pure p
 
 initCredentials :: (FromJSON a) => FilePathSecrets -> IO a
 initCredentials secretFile = do
   dat <- loadSecret secretFile
-  return $ either (\e -> error $ "Could not load secrets from " ++ show secretFile ++ ": " ++ e) id dat
+  pure $ either (\e -> error $ "Could not load secrets from " ++ show secretFile ++ ": " ++ e) id dat
 
 userTemplates :: MonadReader Env m => Maybe Locale -> m (Locale, UserTemplates)
 userTemplates l = forLocale l <$> view usrTemplates
@@ -612,10 +612,10 @@ locationOf ip =
   view geoDb >>= \case
     Just g -> do
       database <- liftIO $ readIORef g
-      return $! do
+      pure $! do
         loc <- GeoIp.geoLocation =<< hush (GeoIp.findGeoData database "en" ip)
-        return $ location (Latitude $ GeoIp.locationLatitude loc) (Longitude $ GeoIp.locationLongitude loc)
-    Nothing -> return Nothing
+        pure $ location (Latitude $ GeoIp.locationLatitude loc) (Longitude $ GeoIp.locationLongitude loc)
+    Nothing -> pure Nothing
 
 --------------------------------------------------------------------------------
 -- Federation
diff --git a/services/brig/src/Brig/Budget.hs b/services/brig/src/Brig/Budget.hs
index b7ac60fc88..cf952a3ed7 100644
--- a/services/brig/src/Brig/Budget.hs
+++ b/services/brig/src/Brig/Budget.hs
@@ -63,18 +63,18 @@ withBudget k b ma = do
   Budget ttl val <- fromMaybe b <$> lookupBudget k
   let remaining = val - 1
   if remaining < 0
-    then return (BudgetExhausted ttl)
+    then pure (BudgetExhausted ttl)
     else do
       a <- ma
       insertBudget k (Budget ttl remaining)
-      return (BudgetedValue a remaining)
+      pure (BudgetedValue a remaining)
 
 -- | Like 'withBudget', but does not decrease budget, only takes a look.
 checkBudget :: MonadClient m => BudgetKey -> Budget -> m (Budgeted ())
 checkBudget k b = do
   Budget ttl val <- fromMaybe b <$> lookupBudget k
   let remaining = val - 1
-  return $
+  pure $
     if remaining < 0
       then BudgetExhausted ttl
       else BudgetedValue () remaining
diff --git a/services/brig/src/Brig/Calling.hs b/services/brig/src/Brig/Calling.hs
index 0b140baf91..48f892c64e 100644
--- a/services/brig/src/Brig/Calling.hs
+++ b/services/brig/src/Brig/Calling.hs
@@ -374,7 +374,7 @@ startWatching w p = void . FS.watchDir w (Path.dropFileName p) predicate
     predicate FS.Unknown {} = False
 
 readTurnList :: FilePath -> IO (Maybe (NonEmpty TurnURI))
-readTurnList = Text.readFile >=> return . fn . mapMaybe (fromByteString . Text.encodeUtf8) . Text.lines
+readTurnList = Text.readFile >=> pure . fn . mapMaybe (fromByteString . Text.encodeUtf8) . Text.lines
   where
     fn [] = Nothing
     fn (x : xs) = Just (x :| xs)
diff --git a/services/brig/src/Brig/Code.hs b/services/brig/src/Brig/Code.hs
index 05fbb72f12..ec7383151e 100644
--- a/services/brig/src/Brig/Code.hs
+++ b/services/brig/src/Brig/Code.hs
@@ -136,13 +136,13 @@ instance Cql Scope where
   toCql CreateScimToken = CqlInt 6
   toCql DeleteTeam = CqlInt 7
 
-  fromCql (CqlInt 1) = return AccountDeletion
-  fromCql (CqlInt 2) = return IdentityVerification
-  fromCql (CqlInt 3) = return PasswordReset
-  fromCql (CqlInt 4) = return AccountLogin
-  fromCql (CqlInt 5) = return AccountApproval
-  fromCql (CqlInt 6) = return CreateScimToken
-  fromCql (CqlInt 7) = return DeleteTeam
+  fromCql (CqlInt 1) = pure AccountDeletion
+  fromCql (CqlInt 2) = pure IdentityVerification
+  fromCql (CqlInt 3) = pure PasswordReset
+  fromCql (CqlInt 4) = pure AccountLogin
+  fromCql (CqlInt 5) = pure AccountApproval
+  fromCql (CqlInt 6) = pure CreateScimToken
+  fromCql (CqlInt 7) = pure DeleteTeam
   fromCql _ = Left "fromCql: Scope: int expected"
 
 newtype Retries = Retries {numRetries :: Word8}
@@ -151,7 +151,7 @@ newtype Retries = Retries {numRetries :: Word8}
 instance Cql Retries where
   ctype = Tagged IntColumn
   toCql = CqlInt . fromIntegral . numRetries
-  fromCql (CqlInt n) = return (Retries (fromIntegral n))
+  fromCql (CqlInt n) = pure (Retries (fromIntegral n))
   fromCql _ = Left "fromCql: Retries: int expected"
 
 --------------------------------------------------------------------------------
@@ -178,7 +178,7 @@ mkKey cfor = liftIO $ do
 mkGen :: MonadIO m => CodeFor -> m Gen
 mkGen cfor = liftIO $ do
   Just sha256 <- getDigestByName "SHA256"
-  return (initGen sha256 cfor)
+  pure (initGen sha256 cfor)
   where
     initGen d (ForEmail e) = mkEmailLinkGen e d
     initGen d _ = mk6DigitGen' cfor d
@@ -187,7 +187,7 @@ mkGen cfor = liftIO $ do
 mk6DigitGen :: MonadIO m => CodeFor -> m Gen
 mk6DigitGen cfor = liftIO $ do
   Just sha256 <- getDigestByName "SHA256"
-  return $ mk6DigitGen' cfor sha256
+  pure $ mk6DigitGen' cfor sha256
 
 mk6DigitGen' :: CodeFor -> Digest -> Gen
 mk6DigitGen' cfor d =
@@ -224,7 +224,7 @@ generate ::
 generate gen scope retries ttl account = do
   let key = genKey gen
   val <- liftIO $ genValue gen
-  return $ mkCode key val
+  pure $ mkCode key val
   where
     mkCode key val =
       Code
@@ -297,14 +297,14 @@ lookup k s = fmap (toCode k s) <$> retry x1 (query1 cql (params LocalQuorum (k,
 -- | Lookup and verify the code for the given key and scope
 -- against the given value.
 verify :: MonadClient m => Key -> Scope -> Value -> m (Maybe Code)
-verify k s v = lookup k s >>= maybe (return Nothing) continue
+verify k s v = lookup k s >>= maybe (pure Nothing) continue
   where
     continue c
-      | codeValue c == v = return (Just c)
+      | codeValue c == v = pure (Just c)
       | codeRetries c > 0 = do
         insert (c {codeRetries = codeRetries c - 1})
-        return Nothing
-      | otherwise = return Nothing
+        pure Nothing
+      | otherwise = pure Nothing
 
 -- | Delete a code associated with the given key and scope.
 delete :: MonadClient m => Key -> Scope -> m ()
diff --git a/services/brig/src/Brig/Data/Activation.hs b/services/brig/src/Brig/Data/Activation.hs
index 7fff629efc..7f20e71948 100644
--- a/services/brig/src/Brig/Data/Activation.hs
+++ b/services/brig/src/Brig/Data/Activation.hs
@@ -96,9 +96,9 @@ activateKey ::
   ExceptT ActivationError m (Maybe ActivationEvent)
 activateKey k c u = verifyCode k c >>= pickUser >>= activate
   where
-    pickUser (uk, u') = maybe (throwE invalidUser) (return . (uk,)) (u <|> u')
+    pickUser (uk, u') = maybe (throwE invalidUser) (pure . (uk,)) (u <|> u')
     activate (key, uid) = do
-      a <- lift (lookupAccount uid) >>= maybe (throwE invalidUser) return
+      a <- lift (lookupAccount uid) >>= maybe (throwE invalidUser) pure
       unless (accountStatus a == Active) $ -- this is never 'PendingActivation' in the flow this function is used in.
         throwE invalidCode
       case userIdentity (accountUser a) of
@@ -107,7 +107,7 @@ activateKey k c u = verifyCode k c >>= pickUser >>= activate
           let ident = foldKey EmailIdentity PhoneIdentity key
           lift $ activateUser uid ident
           let a' = a {accountUser = (accountUser a) {userIdentity = Just ident}}
-          return . Just $ AccountActivated a'
+          pure . Just $ AccountActivated a'
         Just _ -> do
           let usr = accountUser a
               (profileNeedsUpdate, oldKey) =
@@ -118,19 +118,19 @@ activateKey k c u = verifyCode k c >>= pickUser >>= activate
                   usr
            in handleExistingIdentity uid profileNeedsUpdate oldKey key
     handleExistingIdentity uid profileNeedsUpdate oldKey key
-      | oldKey == Just key && not profileNeedsUpdate = return Nothing
+      | oldKey == Just key && not profileNeedsUpdate = pure Nothing
       -- activating existing key and exactly same profile
       -- (can happen when a user clicks on activation links more than once)
       | oldKey == Just key && profileNeedsUpdate = do
         lift $ foldKey (updateEmailAndDeleteEmailUnvalidated uid) (updatePhone uid) key
-        return . Just $ foldKey (EmailActivated uid) (PhoneActivated uid) key
+        pure . Just $ foldKey (EmailActivated uid) (PhoneActivated uid) key
       -- if the key is the same, we only want to update our profile
       | otherwise = do
         lift (runM (codeStoreToCassandra @m @'[Embed m] (E.mkPasswordResetKey uid >>= E.codeDelete)))
         claim key uid
         lift $ foldKey (updateEmailAndDeleteEmailUnvalidated uid) (updatePhone uid) key
         for_ oldKey $ lift . deleteKey
-        return . Just $ foldKey (EmailActivated uid) (PhoneActivated uid) key
+        pure . Just $ foldKey (EmailActivated uid) (PhoneActivated uid) key
       where
         updateEmailAndDeleteEmailUnvalidated :: MonadClient m => UserId -> Email -> m ()
         updateEmailAndDeleteEmailUnvalidated u' email =
@@ -162,7 +162,7 @@ newActivation uk timeout u = do
     insert t k c = do
       key <- liftIO $ mkActivationKey uk
       retry x5 . write keyInsert $ params LocalQuorum (key, t, k, c, u, maxAttempts, round timeout)
-      return $ Activation key c
+      pure $ Activation key c
     genCode =
       ActivationCode . Ascii.unsafeFromText . pack . printf "%06d"
         <$> randIntegerZeroToNMinusOne 1000000
@@ -190,10 +190,10 @@ verifyCode key code = do
     Nothing -> throwE invalidCode
   where
     mkScope "email" k u = case parseEmail k of
-      Just e -> return (userEmailKey e, u)
+      Just e -> pure (userEmailKey e, u)
       Nothing -> throwE invalidCode
     mkScope "phone" k u = case parsePhone k of
-      Just p -> return (userPhoneKey p, u)
+      Just p -> pure (userPhoneKey p, u)
       Nothing -> throwE invalidCode
     mkScope _ _ _ = throwE invalidCode
     countdown = lift . retry x5 . write keyInsert . params LocalQuorum
@@ -202,9 +202,9 @@ verifyCode key code = do
 mkActivationKey :: UserKey -> IO ActivationKey
 mkActivationKey k = do
   d <- liftIO $ getDigestByName "SHA256"
-  d' <- maybe (fail "SHA256 not found") return d
+  d' <- maybe (fail "SHA256 not found") pure d
   let bs = digestBS d' (T.encodeUtf8 $ keyText k)
-  return . ActivationKey $ Ascii.encodeBase64Url bs
+  pure . ActivationKey $ Ascii.encodeBase64Url bs
 
 deleteActivationPair :: MonadClient m => ActivationKey -> m ()
 deleteActivationPair = write keyDelete . params LocalQuorum . Identity
diff --git a/services/brig/src/Brig/Data/Blacklist.hs b/services/brig/src/Brig/Data/Blacklist.hs
index 4ebe61fd7e..9b0c3a45c0 100644
--- a/services/brig/src/Brig/Data/Blacklist.hs
+++ b/services/brig/src/Brig/Data/Blacklist.hs
@@ -42,7 +42,7 @@ insert uk = retry x5 $ write keyInsert (params LocalQuorum (Identity $ keyText u
 
 exists :: MonadClient m => UserKey -> m Bool
 exists uk =
-  (return . isJust) . fmap runIdentity
+  (pure . isJust) . fmap runIdentity
     =<< retry x1 (query1 keySelect (params LocalQuorum (Identity $ keyText uk)))
 
 delete :: MonadClient m => UserKey -> m ()
@@ -80,12 +80,12 @@ getAllPrefixes prefix = do
 existsAnyPrefix :: MonadClient m => Phone -> m Bool
 existsAnyPrefix phone = do
   let prefixes = fromPhonePrefix <$> allPrefixes (fromPhone phone)
-  (not . null) <$> selectPrefixes prefixes
+  not . null <$> selectPrefixes prefixes
 
 selectPrefixes :: MonadClient m => [Text] -> m [ExcludedPrefix]
 selectPrefixes prefixes = do
   results <- retry x1 (query sel (params LocalQuorum (Identity $ prefixes)))
-  return $ (\(p, c) -> ExcludedPrefix p c) <$> results
+  pure $ uncurry ExcludedPrefix <$> results
   where
     sel :: PrepQuery R (Identity [Text]) (PhonePrefix, Text)
     sel = "SELECT prefix, comment FROM excluded_phones WHERE prefix IN ?"
diff --git a/services/brig/src/Brig/Data/Client.hs b/services/brig/src/Brig/Data/Client.hs
index 03ea230140..51b42529a3 100644
--- a/services/brig/src/Brig/Data/Client.hs
+++ b/services/brig/src/Brig/Data/Client.hs
@@ -147,7 +147,7 @@ addClientWithReAuthPolicy reAuthPolicy u newId c maxPermClients loc cps = do
   new <- insert
   let !total = fromIntegral (length clients + if upsert then 0 else 1)
   let old = maybe (filter (not . exists) typed) (const []) limit
-  return (new, old, total)
+  pure (new, old, total)
   where
     limit :: Maybe Int
     limit = case newClientType c of
@@ -170,7 +170,7 @@ addClientWithReAuthPolicy reAuthPolicy u newId c maxPermClients loc cps = do
           prm = (u, newId, now, newClientType c, newClientLabel c, newClientClass c, newClientCookie c, lat, lon, mdl, C.Set . Set.toList <$> cps)
       retry x5 $ write insertClient (params LocalQuorum prm)
       addMLSPublicKeys u newId (Map.assocs (newClientMLSPublicKeys c))
-      return
+      pure
         $! Client
           { clientId = newId,
             clientType = newClientType c,
@@ -265,8 +265,8 @@ updatePrekeys u c pks = do
     check a b = do
       i <- CryptoBox.isPrekey b
       case i of
-        Success n -> return (CryptoBox.prekeyId n == keyId (prekeyId a))
-        _ -> return False
+        Success n -> pure (CryptoBox.prekeyId n == keyId (prekeyId a))
+        _ -> pure False
 
 claimPrekey ::
   ( Log.MonadLogger m,
@@ -298,8 +298,8 @@ claimPrekey u c =
             field "user" (toByteString u)
               . field "client" (toByteString c)
               . msg (val "last resort prekey used")
-      return $ Just (ClientPrekey c (Prekey i k))
-    removeAndReturnPreKey Nothing = return Nothing
+      pure $ Just (ClientPrekey c (Prekey i k))
+    removeAndReturnPreKey Nothing = pure Nothing
 
     pickRandomPrekey :: MonadIO f => [(PrekeyId, Text)] -> f (Maybe (PrekeyId, Text))
     pickRandomPrekey [] = pure Nothing
@@ -309,7 +309,7 @@ claimPrekey u c =
     pickRandomPrekey pks = do
       let pks' = filter (\k -> fst k /= lastPrekeyId) pks
       ind <- liftIO $ randomRIO (0, length pks' - 1)
-      return $ atMay pks' ind
+      pure $ atMay pks' ind
 
 lookupMLSPublicKey ::
   MonadClient m =>
@@ -488,13 +488,13 @@ withOptLock ::
 withOptLock u c ma = go (10 :: Int)
   where
     go !n = do
-      v <- (version =<<) <$> execDyn return get
+      v <- (version =<<) <$> execDyn pure get
       a <- ma
-      r <- execDyn return (put v)
+      r <- execDyn pure (put v)
       case r of
         Nothing | n > 0 -> reportAttemptFailure >> go (n - 1)
-        Nothing -> reportFailureAndLogError >> return a
-        Just _ -> return a
+        Nothing -> reportFailureAndLogError >> pure a
+        Just _ -> pure a
     version :: AWS.GetItemResponse -> Maybe Word32
     version v = conv =<< HashMap.lookup ddbVersion (view AWS.getItemResponse_item v)
       where
@@ -549,13 +549,13 @@ withOptLock u c ma = go (10 :: Int)
           IO (Maybe y)
         execDyn' e m conv cmd = recovering policy handlers (const run)
           where
-            run = execCatch e cmd >>= either handleErr (return . conv)
+            run = execCatch e cmd >>= either handleErr (pure . conv)
             handlers = httpHandlers ++ [const $ EL.handler_ AWS._ConditionalCheckFailedException (pure True)]
             policy = limitRetries 3 <> exponentialBackoff 100000
             handleErr (AWS.ServiceError se) | se ^. AWS.serviceCode == AWS.ErrorCode "ProvisionedThroughputExceeded" = do
               Metrics.counterIncr (Metrics.path "client.opt_lock.provisioned_throughput_exceeded") m
-              return Nothing
-            handleErr _ = return Nothing
+              pure Nothing
+            handleErr _ = pure Nothing
 
 withLocalLock :: (MonadMask m, MonadIO m) => MVar () -> m a -> m a
 withLocalLock l ma = do
diff --git a/services/brig/src/Brig/Data/Connection.hs b/services/brig/src/Brig/Data/Connection.hs
index 428df573f8..906a94d811 100644
--- a/services/brig/src/Brig/Data/Connection.hs
+++ b/services/brig/src/Brig/Data/Connection.hs
@@ -290,7 +290,7 @@ countConnections u r = do
   rels <- retry x1 . query selectStatus $ params One (Identity (tUnqualified u))
   relsRemote <- retry x1 . query selectStatusRemote $ params One (Identity (tUnqualified u))
 
-  return $ foldl' count 0 rels + foldl' count 0 relsRemote
+  pure $ foldl' count 0 rels + foldl' count 0 relsRemote
   where
     selectStatus :: QueryString R (Identity UserId) (Identity RelationWithHistory)
     selectStatus = "SELECT status FROM connection WHERE left = ?"
diff --git a/services/brig/src/Brig/Data/Instances.hs b/services/brig/src/Brig/Data/Instances.hs
index 7b61939285..feeb356b8e 100644
--- a/services/brig/src/Brig/Data/Instances.hs
+++ b/services/brig/src/Brig/Data/Instances.hs
@@ -74,7 +74,7 @@ instance Cql Email where
   ctype = Tagged TextColumn
 
   fromCql (CqlText t) = case parseEmail t of
-    Just e -> return e
+    Just e -> pure e
     Nothing -> Left "fromCql: Invalid email"
   fromCql _ = Left "fromCql: email: CqlText expected"
 
@@ -84,7 +84,7 @@ instance Cql UserSSOId where
   ctype = Tagged TextColumn
 
   fromCql (CqlText t) = case eitherDecode $ cs t of
-    Right i -> return i
+    Right i -> pure i
     Left msg -> Left $ "fromCql: Invalid UserSSOId: " ++ msg
   fromCql _ = Left "fromCql: UserSSOId: CqlText expected"
 
@@ -129,8 +129,8 @@ instance Cql Pict where
   fromCql (CqlList l) = do
     vs <- map (\(Blob lbs) -> lbs) <$> mapM fromCql l
     as <- mapM (note "Failed to read asset" . JSON.decode) vs
-    return $ Pict as
-  fromCql _ = return noPict
+    pure $ Pict as
+  fromCql _ = pure noPict
 
   toCql = toCql . map (Blob . JSON.encode) . fromPict
 
@@ -145,8 +145,8 @@ instance Cql AssetKey where
 instance Cql AssetSize where
   ctype = Tagged IntColumn
 
-  fromCql (CqlInt 0) = return AssetPreview
-  fromCql (CqlInt 1) = return AssetComplete
+  fromCql (CqlInt 0) = pure AssetPreview
+  fromCql (CqlInt 1) = pure AssetComplete
   fromCql n = Left $ "Unexpected asset size: " ++ show n
 
   toCql AssetPreview = CqlInt 0
@@ -171,7 +171,7 @@ instance Cql Asset where
     k <- required "key"
     s <- optional "size"
     case (t :: Int32) of
-      0 -> return $! ImageAsset k s
+      0 -> pure $! ImageAsset k s
       _ -> Left $ "unexpected user asset type: " ++ show t
     where
       required :: Cql r => Text -> Either String r
@@ -201,11 +201,11 @@ instance Cql AccountStatus where
   toCql PendingInvitation = CqlInt 4
 
   fromCql (CqlInt i) = case i of
-    0 -> return Active
-    1 -> return Suspended
-    2 -> return Deleted
-    3 -> return Ephemeral
-    4 -> return PendingInvitation
+    0 -> pure Active
+    1 -> pure Suspended
+    2 -> pure Deleted
+    3 -> pure Ephemeral
+    4 -> pure PendingInvitation
     n -> Left $ "unexpected account status: " ++ show n
   fromCql _ = Left "account status: int expected"
 
@@ -215,9 +215,9 @@ instance Cql ClientType where
   toCql PermanentClientType = CqlInt 1
   toCql LegalHoldClientType = CqlInt 2
 
-  fromCql (CqlInt 0) = return TemporaryClientType
-  fromCql (CqlInt 1) = return PermanentClientType
-  fromCql (CqlInt 2) = return LegalHoldClientType
+  fromCql (CqlInt 0) = pure TemporaryClientType
+  fromCql (CqlInt 1) = pure PermanentClientType
+  fromCql (CqlInt 2) = pure LegalHoldClientType
   fromCql _ = Left "ClientType: Int [0, 2] expected"
 
 instance Cql ClientClass where
@@ -227,10 +227,10 @@ instance Cql ClientClass where
   toCql DesktopClient = CqlInt 2
   toCql LegalHoldClient = CqlInt 3
 
-  fromCql (CqlInt 0) = return PhoneClient
-  fromCql (CqlInt 1) = return TabletClient
-  fromCql (CqlInt 2) = return DesktopClient
-  fromCql (CqlInt 3) = return LegalHoldClient
+  fromCql (CqlInt 0) = pure PhoneClient
+  fromCql (CqlInt 1) = pure TabletClient
+  fromCql (CqlInt 2) = pure DesktopClient
+  fromCql (CqlInt 3) = pure LegalHoldClient
   fromCql _ = Left "ClientClass: Int [0, 3] expected"
 
 instance Cql RawPropertyValue where
@@ -244,7 +244,7 @@ instance Cql Country where
   toCql = toCql . con2Text
 
   fromCql (CqlAscii c) = case parseCountry c of
-    Just c' -> return c'
+    Just c' -> pure c'
     Nothing -> Left "Country: ISO 3166-1-alpha2 expected."
   fromCql _ = Left "Country: ASCII expected"
 
@@ -253,15 +253,15 @@ instance Cql Language where
   toCql = toCql . lan2Text
 
   fromCql (CqlAscii l) = case parseLanguage l of
-    Just l' -> return l'
+    Just l' -> pure l'
     Nothing -> Left "Language: ISO 639-1 expected."
   fromCql _ = Left "Language: ASCII expected"
 
 instance Cql ManagedBy where
   ctype = Tagged IntColumn
 
-  fromCql (CqlInt 0) = return ManagedByWire
-  fromCql (CqlInt 1) = return ManagedByScim
+  fromCql (CqlInt 0) = pure ManagedByWire
+  fromCql (CqlInt 1) = pure ManagedByScim
   fromCql n = Left $ "Unexpected ManagedBy: " ++ show n
 
   toCql ManagedByWire = CqlInt 0
diff --git a/services/brig/src/Brig/Data/LoginCode.hs b/services/brig/src/Brig/Data/LoginCode.hs
index 4ac76a2c42..8a93ebcf48 100644
--- a/services/brig/src/Brig/Data/LoginCode.hs
+++ b/services/brig/src/Brig/Data/LoginCode.hs
@@ -53,7 +53,7 @@ createLoginCode u = do
   now <- liftIO =<< view currentTime
   code <- liftIO genCode
   insertLoginCode u code maxAttempts (ttl `addUTCTime` now)
-  return $! PendingLoginCode code (Timeout ttl)
+  pure $! PendingLoginCode code (Timeout ttl)
   where
     genCode = LoginCode . T.pack . printf "%06d" <$> randIntegerZeroToNMinusOne 1000000
 
@@ -62,18 +62,18 @@ verifyLoginCode u c = do
   code <- retry x1 (query1 codeSelect (params LocalQuorum (Identity u)))
   now <- liftIO =<< view currentTime
   case code of
-    Just (c', _, t) | c == c' && t >= now -> deleteLoginCode u >> return True
-    Just (c', n, t) | n > 1 && t > now -> insertLoginCode u c' (n - 1) t >> return False
-    Just (_, _, _) -> deleteLoginCode u >> return False
-    Nothing -> return False
+    Just (c', _, t) | c == c' && t >= now -> deleteLoginCode u >> pure True
+    Just (c', n, t) | n > 1 && t > now -> insertLoginCode u c' (n - 1) t >> pure False
+    Just (_, _, _) -> deleteLoginCode u >> pure False
+    Nothing -> pure False
 
 lookupLoginCode :: (MonadReader Env m, MonadClient m) => UserId -> m (Maybe PendingLoginCode)
 lookupLoginCode u = do
   now <- liftIO =<< view currentTime
   validate now =<< retry x1 (query1 codeSelect (params LocalQuorum (Identity u)))
   where
-    validate now (Just (c, _, t)) | now < t = return (Just (pending c now t))
-    validate _ _ = return Nothing
+    validate now (Just (c, _, t)) | now < t = pure (Just (pending c now t))
+    validate _ _ = pure Nothing
     pending c now t = PendingLoginCode c (timeout now t)
     timeout now t = Timeout (t `diffUTCTime` now)
 
diff --git a/services/brig/src/Brig/Data/MLS/KeyPackage.hs b/services/brig/src/Brig/Data/MLS/KeyPackage.hs
index 1239eb82b1..a2d6b78459 100644
--- a/services/brig/src/Brig/Data/MLS/KeyPackage.hs
+++ b/services/brig/src/Brig/Data/MLS/KeyPackage.hs
@@ -123,8 +123,8 @@ keyPackageRefSetConvId ref convId = do
           { serialConsistency = Just LocalSerialConsistency
           }
   case updated of
-    [] -> return False
-    [_] -> return True
+    [] -> pure False
+    [_] -> pure True
     _ -> throwM $ ErrorCall "Primary key violation detected mls_key_package_refs.ref"
   where
     q :: PrepQuery W (Domain, ConvId, KeyPackageRef) x
diff --git a/services/brig/src/Brig/Data/User.hs b/services/brig/src/Brig/Data/User.hs
index d60bca1680..1cc046c4e1 100644
--- a/services/brig/src/Brig/Data/User.hs
+++ b/services/brig/src/Brig/Data/User.hs
@@ -132,7 +132,7 @@ newAccount u inv tid mbHandle = do
         (Just (toUUID -> uuid), _) -> pure uuid
         (_, Just uuid) -> pure uuid
         (Nothing, Nothing) -> liftIO nextRandom
-  passwd <- maybe (return Nothing) (fmap Just . liftIO . mkSafePassword) pass
+  passwd <- maybe (pure Nothing) (fmap Just . liftIO . mkSafePassword) pass
   expiry <- case status of
     Ephemeral -> do
       -- Ephemeral users' expiry time is in expires_in (default sessionTokenTimeout) seconds
@@ -140,9 +140,9 @@ newAccount u inv tid mbHandle = do
       let ZAuth.SessionTokenTimeout defTTL = e ^. ZAuth.settings . ZAuth.sessionTokenTimeout
           ttl = maybe defTTL fromRange (newUserExpiresIn u)
       now <- liftIO =<< view currentTime
-      return . Just . toUTCTimeMillis $ addUTCTime (fromIntegral ttl) now
-    _ -> return Nothing
-  return (UserAccount (user uid domain (locale defLoc) expiry) status, passwd)
+      pure . Just . toUTCTimeMillis $ addUTCTime (fromIntegral ttl) now
+    _ -> pure Nothing
+  pure (UserAccount (user uid domain (locale defLoc) expiry) status, passwd)
   where
     ident = newUserIdentity u
     pass = newUserPassword u
@@ -162,7 +162,7 @@ newAccountInviteViaScim :: (MonadClient m, MonadReader Env m) => UserId -> TeamI
 newAccountInviteViaScim uid tid locale name email = do
   defLoc <- setDefaultUserLocale <$> view settings
   domain <- viewFederationDomain
-  return (UserAccount (user domain (fromMaybe defLoc locale)) PendingInvitation)
+  pure (UserAccount (user domain (fromMaybe defLoc locale)) PendingInvitation)
   where
     user domain loc =
       User
@@ -703,7 +703,7 @@ toUserAccount
     managed_by
     ) =
     let ident = toIdentity activated email phone ssoid
-        deleted = maybe False (== Deleted) status
+        deleted = Just Deleted == status
         expiration = if status == Just Ephemeral then expires else Nothing
         loc = toLocale defaultLocale (lan, con)
         svc = newServiceRef <$> sid <*> pid
@@ -777,7 +777,7 @@ toUsers domain defaultLocale havePendingInvitations = fmap mk . filter fp
         managed_by
         ) =
         let ident = toIdentity activated email phone ssoid
-            deleted = maybe False (== Deleted) status
+            deleted = Just Deleted == status
             expiration = if status == Just Ephemeral then expires else Nothing
             loc = toLocale defaultLocale (lan, con)
             svc = newServiceRef <$> sid <*> pid
diff --git a/services/brig/src/Brig/Data/UserKey.hs b/services/brig/src/Brig/Data/UserKey.hs
index d9afe3af53..027fbac7d1 100644
--- a/services/brig/src/Brig/Data/UserKey.hs
+++ b/services/brig/src/Brig/Data/UserKey.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 -- This file is part of the Wire Server implementation.
 --
 -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
@@ -70,8 +68,8 @@ instance Cql UKHashType where
   ctype = Tagged IntColumn
 
   fromCql (CqlInt i) = case i of
-    0 -> return UKHashPhone
-    1 -> return UKHashEmail
+    0 -> pure UKHashPhone
+    1 -> pure UKHashEmail
     n -> Left $ "unexpected hashtype: " ++ show n
   fromCql _ = Left "userkeyhashtype: int expected"
 
@@ -85,7 +83,7 @@ instance Cql UserKeyHash where
 
   fromCql (CqlBlob lbs) = case MH.decode (toStrict lbs) of
     Left e -> Left ("userkeyhash: " ++ e)
-    Right h -> return $ UserKeyHash h
+    Right h -> pure $ UserKeyHash h
   fromCql _ = Left "userkeyhash: expected blob"
 
   toCql (UserKeyHash d) = CqlBlob $ MH.encode (MH.algorithm d) (MH.digest d)
@@ -129,7 +127,7 @@ claimKey ::
 claimKey k u = do
   free <- keyAvailable k (Just u)
   when free (insertKey u k)
-  return free
+  pure free
 
 -- | Check whether a 'UserKey' is available.
 -- A key is available if it is not already actived for another user or
@@ -144,8 +142,8 @@ keyAvailable ::
 keyAvailable k u = do
   o <- lookupKey k
   case (o, u) of
-    (Nothing, _) -> return True
-    (Just x, Just y) | x == y -> return True
+    (Nothing, _) -> pure True
+    (Just x, Just y) | x == y -> pure True
     (Just x, _) -> not <$> User.isActivated x
 
 lookupKey :: MonadClient m => UserKey -> m (Maybe UserId)
@@ -170,7 +168,7 @@ hashKey :: MonadReader Env m => UserKey -> m UserKeyHash
 hashKey uk = do
   d <- view digestSHA256
   let d' = digestBS d $ T.encodeUtf8 (keyText uk)
-  return . UserKeyHash $
+  pure . UserKeyHash $
     MH.MultihashDigest MH.SHA256 (B.length d') d'
 
 lookupPhoneHashes :: MonadClient m => [ByteString] -> m [(ByteString, UserId)]
diff --git a/services/brig/src/Brig/Data/UserPendingActivation.hs b/services/brig/src/Brig/Data/UserPendingActivation.hs
index 2388479446..23a5668428 100644
--- a/services/brig/src/Brig/Data/UserPendingActivation.hs
+++ b/services/brig/src/Brig/Data/UserPendingActivation.hs
@@ -1,5 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
-
 -- This file is part of the Wire Server implementation.
 --
 -- Copyright (C) 2022 Wire Swiss GmbH <opensource@wire.com>
diff --git a/services/brig/src/Brig/IO/Intra.hs b/services/brig/src/Brig/IO/Intra.hs
index afbdec1a85..1a17770abb 100644
--- a/services/brig/src/Brig/IO/Intra.hs
+++ b/services/brig/src/Brig/IO/Intra.hs
@@ -173,7 +173,7 @@ onConnectionEvent orig conn evt = do
       orig
       Push.RouteAny
       conn
-      (return $ list1 from [])
+      (pure $ list1 from [])
 
 onPropertyEvent ::
   -- | Originator of the event.
@@ -189,7 +189,7 @@ onPropertyEvent orig conn e =
       orig
       Push.RouteDirect
       (Just conn)
-      (return $ list1 orig [])
+      (pure $ list1 orig [])
 
 onClientEvent ::
   -- | Originator of the event.
@@ -221,13 +221,13 @@ updateSearchIndex ::
   m ()
 updateSearchIndex orig e = case e of
   -- no-ops
-  UserCreated {} -> return ()
+  UserCreated {} -> pure ()
   UserIdentityUpdated UserIdentityUpdatedData {..} -> do
     when (isJust eiuEmail) $ Search.reindex orig
-  UserIdentityRemoved {} -> return ()
-  UserLegalHoldDisabled {} -> return ()
-  UserLegalHoldEnabled {} -> return ()
-  LegalHoldClientRequested {} -> return ()
+  UserIdentityRemoved {} -> pure ()
+  UserLegalHoldDisabled {} -> pure ()
+  UserLegalHoldEnabled {} -> pure ()
+  LegalHoldClientRequested {} -> pure ()
   UserSuspended {} -> Search.reindex orig
   UserResumed {} -> Search.reindex orig
   UserActivated {} -> Search.reindex orig
@@ -258,7 +258,7 @@ journalEvent orig e = case e of
   UserDeleted {} ->
     Journal.userDelete orig
   _ ->
-    return ()
+    pure ()
 
 -------------------------------------------------------------------------------
 -- Low-Level Event Notification
@@ -282,9 +282,9 @@ dispatchNotifications ::
   UserEvent ->
   m ()
 dispatchNotifications orig conn e = case e of
-  UserCreated {} -> return ()
-  UserSuspended {} -> return ()
-  UserResumed {} -> return ()
+  UserCreated {} -> pure ()
+  UserSuspended {} -> pure ()
+  UserResumed {} -> pure ()
   LegalHoldClientRequested {} -> notifyContacts event orig Push.RouteAny conn
   UserLegalHoldDisabled {} -> notifyContacts event orig Push.RouteAny conn
   UserLegalHoldEnabled {} -> notifyContacts event orig Push.RouteAny conn
@@ -334,7 +334,7 @@ notifyUserDeletionRemotes ::
 notifyUserDeletionRemotes deleted = do
   runConduit $
     Data.lookupRemoteConnectedUsersC deleted (fromInteger (natVal (Proxy @UserDeletedNotificationMaxConnections)))
-      .| C.mapM_ (fanoutNotifications)
+      .| C.mapM_ fanoutNotifications
   where
     fanoutNotifications :: [Remote UserId] -> m ()
     fanoutNotifications = mapM_ notifyBackend . bucketRemote
@@ -482,7 +482,7 @@ fork u ma = do
   let logErr e = ExLog.err g $ request r ~~ user u ~~ msg (show e)
   withRunInIO $ \lower ->
     void . liftIO . forkIO $
-      either logErr (const $ return ())
+      either logErr (const $ pure ())
         =<< runExceptT (syncIO $ lower ma)
   where
     request = field "request" . unRequestId
@@ -542,8 +542,8 @@ notifyContacts events orig route conn = do
     screenMemberList :: Maybe Team.TeamMemberList -> m [UserId]
     screenMemberList (Just mems)
       | mems ^. Team.teamMemberListType == Team.ListComplete =
-        return $ fmap (view Team.userId) (mems ^. Team.teamMembers)
-    screenMemberList _ = return []
+        pure $ fmap (view Team.userId) (mems ^. Team.teamMembers)
+    screenMemberList _ = pure []
 
 -- Event Serialisation:
 
@@ -754,7 +754,7 @@ createLocalConnectConv from to cname conn = do
           . lbytes (encode $ Connect (qUntagged to) Nothing cname Nothing)
           . expect2xx
   r <- galleyRequest POST req
-  maybe (error "invalid conv id") return $
+  maybe (error "invalid conv id") pure $
     fromByteString $
       getHeader' "Location" r
 
@@ -911,7 +911,7 @@ getConv usr cnv = do
   rs <- galleyRequest GET req
   case Bilge.statusCode rs of
     200 -> Just <$> decodeBody "galley" rs
-    _ -> return Nothing
+    _ -> pure Nothing
   where
     req =
       paths ["conversations", toByteString' cnv]
@@ -960,7 +960,7 @@ getTeamConv usr tid cnv = do
   rs <- galleyRequest GET req
   case Bilge.statusCode rs of
     200 -> Just <$> decodeBody "galley" rs
-    _ -> return Nothing
+    _ -> pure Nothing
   where
     req =
       paths ["teams", toByteString' tid, "conversations", toByteString' cnv]
@@ -1110,10 +1110,10 @@ checkUserCanJoinTeam tid = do
     remote "galley"
       . msg (val "Check if can add member to team")
   rs <- galleyRequest GET req
-  return $ case Bilge.statusCode rs of
+  pure $ case Bilge.statusCode rs of
     200 -> Nothing
     _ -> case decodeBody "galley" rs of
-      Just (e :: Wai.Error) -> return e
+      Just (e :: Wai.Error) -> pure e
       Nothing -> error ("Invalid response from galley: " <> show rs)
   where
     req =
@@ -1138,7 +1138,7 @@ addTeamMember u tid (minvmeta, role) = do
     remote "galley"
       . msg (val "Adding member to team")
   rs <- galleyRequest POST req
-  return $ case Bilge.statusCode rs of
+  pure $ case Bilge.statusCode rs of
     200 -> True
     _ -> False
   where
@@ -1170,10 +1170,10 @@ createTeam u t@(Team.BindingNewTeam bt) teamid = do
       . msg (val "Creating Team")
   r <- galleyRequest PUT $ req teamid
   tid <-
-    maybe (error "invalid team id") return $
+    maybe (error "invalid team id") pure $
       fromByteString $
         getHeader' "Location" r
-  return (CreateUserTeam tid $ fromRange (bt ^. Team.newTeamName))
+  pure (CreateUserTeam tid $ fromRange (bt ^. Team.newTeamName))
   where
     req tid =
       paths ["i", "teams", toByteString' tid]
@@ -1201,7 +1201,7 @@ getTeamMember u tid = do
   rs <- galleyRequest GET req
   case Bilge.statusCode rs of
     200 -> Just <$> decodeBody "galley" rs
-    _ -> return Nothing
+    _ -> pure Nothing
   where
     req =
       paths ["i", "teams", toByteString' tid, "members", toByteString' u]
@@ -1265,7 +1265,7 @@ getTeamContacts u = do
   rs <- galleyRequest GET req
   case Bilge.statusCode rs of
     200 -> Just <$> decodeBody "galley" rs
-    _ -> return Nothing
+    _ -> pure Nothing
   where
     req =
       paths ["i", "users", toByteString' u, "team", "members"]
@@ -1287,7 +1287,7 @@ getTeamId u = do
   rs <- galleyRequest GET req
   case Bilge.statusCode rs of
     200 -> Just <$> decodeBody "galley" rs
-    _ -> return Nothing
+    _ -> pure Nothing
   where
     req =
       paths ["i", "users", toByteString' u, "team"]
diff --git a/services/brig/src/Brig/IO/Journal.hs b/services/brig/src/Brig/IO/Journal.hs
index c612c4fc7a..2ebe6b102a 100644
--- a/services/brig/src/Brig/IO/Journal.hs
+++ b/services/brig/src/Brig/IO/Journal.hs
@@ -51,7 +51,7 @@ userActivate :: (MonadReader Env m, MonadIO m) => User -> m ()
 userActivate u@User {..} = journalEvent UserEvent'USER_ACTIVATE userId (userEmail u) (Just userLocale) userTeam (Just userDisplayName)
 
 userUpdate :: (MonadReader Env m, MonadIO m) => UserId -> Maybe Email -> Maybe Locale -> Maybe Name -> m ()
-userUpdate uid em loc nm = journalEvent UserEvent'USER_UPDATE uid em loc Nothing nm
+userUpdate uid em loc = journalEvent UserEvent'USER_UPDATE uid em loc Nothing
 
 userEmailRemove :: (MonadReader Env m, MonadIO m) => UserId -> Email -> m ()
 userEmailRemove uid em = journalEvent UserEvent'USER_EMAIL_REMOVE uid (Just em) Nothing Nothing Nothing
@@ -67,7 +67,7 @@ journalEvent typ uid em loc tid nm =
     let userEvent :: UserEvent =
           defMessage
             & U.eventType .~ typ
-            & U.userId .~ (toBytes uid)
+            & U.userId .~ toBytes uid
             & U.utcTime .~ ts
             & U.maybe'email .~ (toByteString' <$> em)
             & U.maybe'locale .~ (pack . show <$> loc)
diff --git a/services/brig/src/Brig/Index/Options.hs b/services/brig/src/Brig/Index/Options.hs
index 5935684a41..c614172794 100644
--- a/services/brig/src/Brig/Index/Options.hs
+++ b/services/brig/src/Brig/Index/Options.hs
@@ -200,27 +200,25 @@ elasticSettingsParser =
           )
     templateParser :: Parser (Maybe ES.TemplateName) =
       ES.TemplateName
-        <$$> ( optional
-                 ( option
-                     str
-                     ( long "delete-template"
-                         <> metavar "TEMPLATE_NAME"
-                         <> help "Delete this ES template before creating a new index"
-                     )
-                 )
-             )
+        <$$> optional
+          ( option
+              str
+              ( long "delete-template"
+                  <> metavar "TEMPLATE_NAME"
+                  <> help "Delete this ES template before creating a new index"
+              )
+          )
 
 cassandraSettingsParser :: Parser CassandraSettings
 cassandraSettingsParser =
   CassandraSettings
-    <$> ( strOption
-            ( long "cassandra-host"
-                <> metavar "HOST"
-                <> help "Cassandra Host."
-                <> value (_cHost localCassandraSettings)
-                <> showDefault
-            )
-        )
+    <$> strOption
+      ( long "cassandra-host"
+          <> metavar "HOST"
+          <> help "Cassandra Host."
+          <> value (_cHost localCassandraSettings)
+          <> showDefault
+      )
     <*> option
       auto
       ( long "cassandra-port"
@@ -257,36 +255,33 @@ reindexToAnotherIndexSettingsParser =
                   <> help "Elasticsearch index name to reindex to"
               )
         )
-    <*> ( option
-            auto
-            ( long "timeout"
-                <> metavar "SECONDS"
-                <> help "Number of seconds to wait for reindexing to complete. The reindexing will not be cancelled when this timeout expires."
-                <> value 600
-                <> showDefault
-            )
-        )
+    <*> option
+      auto
+      ( long "timeout"
+          <> metavar "SECONDS"
+          <> help "Number of seconds to wait for reindexing to complete. The reindexing will not be cancelled when this timeout expires."
+          <> value 600
+          <> showDefault
+      )
 
 galleyEndpointParser :: Parser Endpoint
 galleyEndpointParser =
   Endpoint
-    <$> ( strOption
-            ( long "galley-host"
-                <> help "Hostname or IP address of galley"
-                <> metavar "HOSTNAME"
-                <> value "localhost"
-                <> showDefault
-            )
-        )
-    <*> ( option
-            auto
-            ( long "galley-port"
-                <> help "Port number of galley"
-                <> metavar "PORT"
-                <> value 8085
-                <> showDefault
-            )
-        )
+    <$> strOption
+      ( long "galley-host"
+          <> help "Hostname or IP address of galley"
+          <> metavar "HOSTNAME"
+          <> value "localhost"
+          <> showDefault
+      )
+    <*> option
+      auto
+      ( long "galley-port"
+          <> help "Port number of galley"
+          <> metavar "PORT"
+          <> value 8085
+          <> showDefault
+      )
 
 commandParser :: Parser Command
 commandParser =
@@ -295,7 +290,7 @@ commandParser =
         "create"
         ( info
             (Create <$> elasticSettingsParser <*> galleyEndpointParser)
-            (progDesc ("Create the ES user index, if it doesn't already exist. "))
+            (progDesc "Create the ES user index, if it doesn't already exist. ")
         )
         <> command
           "update-mapping"
@@ -307,7 +302,7 @@ commandParser =
           "reset"
           ( info
               (Reset <$> restrictedElasticSettingsParser <*> galleyEndpointParser)
-              (progDesc ("Delete and re-create the ES user index. Only works on a test index (directory_test)."))
+              (progDesc "Delete and re-create the ES user index. Only works on a test index (directory_test).")
           )
         <> command
           "reindex"
diff --git a/services/brig/src/Brig/InternalEvent/Types.hs b/services/brig/src/Brig/InternalEvent/Types.hs
index b5cf86800d..c9ac85e3ac 100644
--- a/services/brig/src/Brig/InternalEvent/Types.hs
+++ b/services/brig/src/Brig/InternalEvent/Types.hs
@@ -36,8 +36,8 @@ data InternalNotificationType
 
 instance FromJSON InternalNotificationType where
   parseJSON = \case
-    "user.delete" -> return UserDeletion
-    "service.delete" -> return ServiceDeletion
+    "user.delete" -> pure UserDeletion
+    "service.delete" -> pure ServiceDeletion
     x -> fail $ "InternalNotificationType: Unknown type " <> show x
 
 instance ToJSON InternalNotificationType where
diff --git a/services/brig/src/Brig/Password.hs b/services/brig/src/Brig/Password.hs
index d5889d1be7..9c52d9268e 100644
--- a/services/brig/src/Brig/Password.hs
+++ b/services/brig/src/Brig/Password.hs
@@ -42,7 +42,7 @@ instance Show Password where
 instance Cql Password where
   ctype = Tagged BlobColumn
 
-  fromCql (CqlBlob lbs) = return . Password . EncryptedPass $ toStrict lbs
+  fromCql (CqlBlob lbs) = pure . Password . EncryptedPass $ toStrict lbs
   fromCql _ = Left "password: expected blob"
 
   toCql = CqlBlob . fromStrict . getEncryptedPass . fromPassword
diff --git a/services/brig/src/Brig/Phone.hs b/services/brig/src/Brig/Phone.hs
index c8c54f048a..44eb72f796 100644
--- a/services/brig/src/Brig/Phone.hs
+++ b/services/brig/src/Brig/Phone.hs
@@ -93,12 +93,12 @@ sendCall call = unless (isTestPhone $ Nexmo.callTo call) $ do
         Nexmo.CallUnroutable -> unreachable ex
         Nexmo.CallDestinationBarred -> barred ex
         _ -> throwM ex
-      Right _ -> return ()
+      Right _ -> pure ()
   where
     nexmoHandlers =
       httpHandlers
         ++ [ const . Handler $ \(ex :: Nexmo.CallErrorResponse) ->
-               return $ case Nexmo.caStatus ex of
+               pure $ case Nexmo.caStatus ex of
                  Nexmo.CallThrottled -> True
                  Nexmo.CallInternal -> True
                  _ -> False
@@ -140,7 +140,7 @@ sendSms loc SMSMessage {..} = unless (isTestPhone smsTo) $ do
           21610 -> barred ex'
           -- A real problem
           _ -> throwM ex'
-        Right () -> return ()
+        Right () -> pure ()
   where
     sendNexmoSms :: (MonadIO f, MonadReader Env f) => Manager -> f ()
     sendNexmoSms mgr = do
@@ -167,14 +167,14 @@ sendSms loc SMSMessage {..} = unless (isTestPhone smsTo) $ do
           Twilio.sendMessage crd mgr (Twilio.Message smsFrom smsTo smsText)
     nexmoFailed =
       [ Handler $ \(ex :: HttpException) ->
-          return (Just (SomeException ex)),
+          pure (Just (SomeException ex)),
         Handler $ \(ex :: Nexmo.MessageErrorResponse) ->
-          return (Just (SomeException ex))
+          pure (Just (SomeException ex))
       ]
     nexmoHandlers =
       httpHandlers
         ++ [ const . Handler $ \(ex :: Nexmo.MessageErrorResponse) ->
-               return $ case Nexmo.erStatus ex of
+               pure $ case Nexmo.erStatus ex of
                  Nexmo.MessageThrottled -> True
                  Nexmo.MessageInternal -> True
                  Nexmo.MessageCommunicationFailed -> True
@@ -183,7 +183,7 @@ sendSms loc SMSMessage {..} = unless (isTestPhone smsTo) $ do
     twilioHandlers =
       httpHandlers
         ++ [ const . Handler $ \(ex :: Twilio.ErrorResponse) ->
-               return $ case Twilio.errStatus ex of
+               pure $ case Twilio.errStatus ex of
                  20429 -> True -- Too Many Requests
                  20500 -> True -- Internal Server Error
                  20503 -> True -- Temporarily Unavailable
@@ -204,7 +204,7 @@ sendSms loc SMSMessage {..} = unless (isTestPhone smsTo) $ do
 -- E.164 format of the given phone number on success.
 validatePhone :: (MonadClient m, MonadReader Env m) => Phone -> m (Maybe Phone)
 validatePhone (Phone p)
-  | isTestPhone p = return (Just (Phone p))
+  | isTestPhone p = pure (Just (Phone p))
   | otherwise = do
     c <- view twilioCreds
     m <- view httpManager
@@ -214,8 +214,8 @@ validatePhone (Phone p)
           const $
             Twilio.lookupPhone c m p LookupNoDetail Nothing
     case r of
-      Right x -> return (Just (Phone (Twilio.lookupE164 x)))
-      Left e | Twilio.errStatus e == 404 -> return Nothing
+      Right x -> pure (Just (Phone (Twilio.lookupE164 x)))
+      Left e | Twilio.errStatus e == 404 -> pure Nothing
       Left e -> throwM e
 
 isTestPhone :: Text -> Bool
@@ -254,7 +254,7 @@ withSmsBudget phone go = do
         msg (val "SMS budget deducted.")
           ~~ field "budget" b
           ~~ field "phone" phone
-      return a
+      pure a
 
 --------------------------------------------------------------------------------
 -- Voice Call Budgeting
@@ -289,7 +289,7 @@ withCallBudget phone go = do
         msg (val "Voice call budget deducted.")
           ~~ field "budget" b
           ~~ field "phone" phone
-      return a
+      pure a
 
 --------------------------------------------------------------------------------
 -- Unique Keys
diff --git a/services/brig/src/Brig/Provider/API.hs b/services/brig/src/Brig/Provider/API.hs
index eb273b4402..8a8f96c561 100644
--- a/services/brig/src/Brig/Provider/API.hs
+++ b/services/brig/src/Brig/Provider/API.hs
@@ -332,7 +332,7 @@ newAccountH req = do
 newAccount :: Public.NewProvider -> (Handler r) Public.NewProviderResponse
 newAccount new = do
   email <- case validateEmail (Public.newProviderEmail new) of
-    Right em -> return em
+    Right em -> pure em
     Left _ -> throwStd (errorToWai @'InvalidEmail)
   let name = Public.newProviderName new
   let pass = Public.newProviderPassword new
@@ -345,7 +345,7 @@ newAccount new = do
     Nothing -> do
       newPass <- genPassword
       safePass <- mkSafePassword newPass
-      return (safePass, Just newPass)
+      pure (safePass, Just newPass)
   pid <- wrapClientE $ DB.insertAccount name safePass url descr
   gen <- Code.mkGen (Code.ForEmail email)
   code <-
@@ -359,7 +359,7 @@ newAccount new = do
   let key = Code.codeKey code
   let val = Code.codeValue code
   lift $ sendActivationMail name email key val False
-  return $ Public.NewProviderResponse pid newPass
+  pure $ Public.NewProviderResponse pid newPass
 
 activateAccountKeyH :: Code.Key ::: Code.Value -> (Handler r) Response
 activateAccountKeyH (key ::: val) = do
@@ -370,23 +370,23 @@ activateAccountKey :: Code.Key -> Code.Value -> (Handler r) (Maybe Public.Provid
 activateAccountKey key val = do
   c <- wrapClientE (Code.verify key Code.IdentityVerification val) >>= maybeInvalidCode
   (pid, email) <- case (Code.codeAccount c, Code.codeForEmail c) of
-    (Just p, Just e) -> return (Id p, e)
+    (Just p, Just e) -> pure (Id p, e)
     _ -> throwStd (errorToWai @'InvalidCode)
   (name, memail, _url, _descr) <- wrapClientE (DB.lookupAccountData pid) >>= maybeInvalidCode
   case memail of
-    Just email' | email == email' -> return Nothing
+    Just email' | email == email' -> pure Nothing
     Just email' -> do
       -- Ensure we remove any pending password reset
       gen <- Code.mkGen (Code.ForEmail email')
       lift $ wrapClient $ Code.delete (Code.genKey gen) Code.PasswordReset
       -- Activate the new and remove the old key
       activate pid (Just email') email
-      return . Just $ Public.ProviderActivationResponse email
+      pure . Just $ Public.ProviderActivationResponse email
     -- Immediate approval for everybody (for now).
     Nothing -> do
       activate pid Nothing email
       lift $ sendApprovalConfirmMail name email
-      return . Just $ Public.ProviderActivationResponse email
+      pure . Just $ Public.ProviderActivationResponse email
 
 getActivationCodeH :: Public.Email -> (Handler r) Response
 getActivationCodeH e = do
@@ -396,11 +396,11 @@ getActivationCodeH e = do
 getActivationCode :: Public.Email -> (Handler r) FoundActivationCode
 getActivationCode e = do
   email <- case validateEmail e of
-    Right em -> return em
+    Right em -> pure em
     Left _ -> throwStd (errorToWai @'InvalidEmail)
   gen <- Code.mkGen (Code.ForEmail email)
   code <- wrapClientE $ Code.lookup (Code.genKey gen) Code.IdentityVerification
-  maybe (throwStd activationKeyNotFound) (return . FoundActivationCode) code
+  maybe (throwStd activationKeyNotFound) (pure . FoundActivationCode) code
 
 newtype FoundActivationCode = FoundActivationCode Code.Code
 
@@ -514,7 +514,7 @@ updateAccountEmailH (pid ::: req) = do
 updateAccountEmail :: ProviderId -> Public.EmailUpdate -> (Handler r) ()
 updateAccountEmail pid (Public.EmailUpdate new) = do
   email <- case validateEmail new of
-    Right em -> return em
+    Right em -> pure em
     Left _ -> throwStd (errorToWai @'InvalidEmail)
   let emailKey = mkEmailKey email
   wrapClientE (DB.lookupKey emailKey) >>= mapM_ (const $ throwStd emailExists)
@@ -559,10 +559,10 @@ addService pid new = do
   let assets = newServiceAssets new
   let tags = fromRange (newServiceTags new)
   (pk, fp) <- validateServiceKey pubkey >>= maybeInvalidServiceKey
-  token <- maybe randServiceToken return (newServiceToken new)
+  token <- maybe randServiceToken pure (newServiceToken new)
   sid <- wrapClientE $ DB.insertService pid name summary descr baseUrl token pk fp assets tags
   let rstoken = maybe (Just token) (const Nothing) (newServiceToken new)
-  return $ Public.NewServiceResponse sid rstoken
+  pure $ Public.NewServiceResponse sid rstoken
 
 listServicesH :: ProviderId -> (Handler r) Response
 listServicesH pid = do
@@ -736,8 +736,8 @@ deleteAccount ::
   Public.DeleteProvider ->
   ExceptT Error m ()
 deleteAccount pid del = do
-  prov <- (DB.lookupAccount pid) >>= maybeInvalidProvider
-  pass <- (DB.lookupPassword pid) >>= maybeBadCredentials
+  prov <- DB.lookupAccount pid >>= maybeInvalidProvider
+  pass <- DB.lookupPassword pid >>= maybeBadCredentials
   unless (verifyPassword (deleteProviderPassword del) pass) $
     throwStd (errorToWai @'BadCredentials)
   svcs <- DB.listServices pid
@@ -828,7 +828,7 @@ getServiceTagListH () = do
   json <$> getServiceTagList ()
 
 getServiceTagList :: () -> Monad m => m Public.ServiceTagList
-getServiceTagList () = return (Public.ServiceTagList allTags)
+getServiceTagList () = pure (Public.ServiceTagList allTags)
   where
     allTags = [(minBound :: Public.ServiceTag) ..]
 
@@ -856,11 +856,11 @@ updateServiceWhitelist uid con tid upd = do
   -- Add to various tables
   whitelisted <- wrapClientE $ DB.getServiceWhitelistStatus tid pid sid
   case (whitelisted, newWhitelisted) of
-    (False, False) -> return UpdateServiceWhitelistRespUnchanged
-    (True, True) -> return UpdateServiceWhitelistRespUnchanged
+    (False, False) -> pure UpdateServiceWhitelistRespUnchanged
+    (True, True) -> pure UpdateServiceWhitelistRespUnchanged
     (False, True) -> do
       wrapClientE $ DB.insertServiceWhitelist tid pid sid
-      return UpdateServiceWhitelistRespChanged
+      pure UpdateServiceWhitelistRespChanged
     (True, False) -> do
       -- When the service is de-whitelisted, remove its bots from team
       -- conversations
@@ -876,7 +876,7 @@ updateServiceWhitelist uid con tid upd = do
                   )
               )
       wrapClientE $ DB.deleteServiceWhitelist (Just tid) pid sid
-      return UpdateServiceWhitelistRespChanged
+      pure UpdateServiceWhitelistRespChanged
 
 addBotH :: UserId ::: ConnId ::: ConvId ::: JsonRequest Public.AddBot -> (Handler r) Response
 addBotH (zuid ::: zcon ::: cid ::: req) = do
@@ -947,7 +947,7 @@ addBot zuid zcon cid add = do
 
   -- Add the bot to the conversation
   ev <- lift $ RPC.addBotMember zuid zcon cid bid (clientId clt) pid sid
-  return $
+  pure $
     Public.AddBotResponse
       { Public.rsAddBotId = bid,
         Public.rsAddBotClient = bcl,
@@ -973,9 +973,9 @@ removeBot zusr zcon cid bid = do
   let busr = botUserId bid
   let bot = List.find ((== busr) . qUnqualified . omQualifiedId) (cmOthers mems)
   case bot >>= omService of
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
     Just _ -> do
-      lift $ Public.RemoveBotResponse <$$> (wrapHttpClient $ deleteBot zusr (Just zcon) bid cid)
+      lift $ Public.RemoveBotResponse <$$> wrapHttpClient (deleteBot zusr (Just zcon) bid cid)
 
 --------------------------------------------------------------------------------
 -- Bot API
@@ -988,7 +988,7 @@ botGetSelfH bot = do
 botGetSelf :: BotId -> (Handler r) Public.UserProfile
 botGetSelf bot = do
   p <- lift $ wrapClient $ User.lookupUser NoPendingInvitations (botUserId bot)
-  maybe (throwStd (errorToWai @'UserNotFound)) (return . (`Public.publicProfile` UserLegalHoldNoConsent)) p
+  maybe (throwStd (errorToWai @'UserNotFound)) (pure . (`Public.publicProfile` UserLegalHoldNoConsent)) p
 
 botGetClientH :: BotId -> (Handler r) Response
 botGetClientH bot = do
@@ -1008,7 +1008,7 @@ botListPrekeys :: BotId -> (Handler r) [Public.PrekeyId]
 botListPrekeys bot = do
   clt <- lift $ listToMaybe <$> wrapClient (User.lookupClients (botUserId bot))
   case clientId <$> clt of
-    Nothing -> return []
+    Nothing -> pure []
     Just ci -> lift (wrapClient $ User.lookupPrekeyIds (botUserId bot) ci)
 
 botUpdatePrekeysH :: BotId ::: JsonRequest Public.UpdateBotPrekeys -> (Handler r) Response
@@ -1045,7 +1045,7 @@ botListUserProfilesH uids = do
 botListUserProfiles :: List UserId -> (Handler r) [Public.BotUserView]
 botListUserProfiles uids = do
   us <- lift . wrapClient $ User.lookupUsers NoPendingInvitations (fromList uids)
-  return (map mkBotUserView us)
+  pure (map mkBotUserView us)
 
 botGetUserClientsH :: UserId -> (Handler r) Response
 botGetUserClientsH uid = do
@@ -1069,7 +1069,7 @@ botDeleteSelf bid cid = do
   bot <- lift . wrapClient $ User.lookupUser NoPendingInvitations (botUserId bid)
   _ <- maybeInvalidBot (userService =<< bot)
   _ <- lift $ wrapHttpClient $ deleteBot (botUserId bid) Nothing bid cid
-  return ()
+  pure ()
 
 --------------------------------------------------------------------------------
 -- Utilities
@@ -1129,28 +1129,28 @@ deleteBot zusr zcon bid cid = do
   -- TODO: Consider if we can actually delete the bot user entirely,
   -- i.e. not just marking the account as deleted.
   void $ runExceptT $ User.updateStatus buid Deleted
-  return ev
+  pure ev
 
 validateServiceKey :: MonadIO m => Public.ServiceKeyPEM -> m (Maybe (Public.ServiceKey, Fingerprint Rsa))
 validateServiceKey pem =
   liftIO $
     readPublicKey >>= \pk ->
       case SSL.toPublicKey =<< pk of
-        Nothing -> return Nothing
+        Nothing -> pure Nothing
         Just pk' -> do
           Just sha <- SSL.getDigestByName "SHA256"
           let size = SSL.rsaSize (pk' :: SSL.RSAPubKey)
           if size < minRsaKeySize
-            then return Nothing
+            then pure Nothing
             else do
               fpr <- Fingerprint <$> SSL.rsaFingerprint sha pk'
               let bits = fromIntegral size * 8
               let key = Public.ServiceKey Public.RsaServiceKey bits pem
-              return $ Just (key, fpr)
+              pure $ Just (key, fpr)
   where
     readPublicKey =
       handleAny
-        (const $ return Nothing)
+        (const $ pure Nothing)
         (SSL.readPublicKey (LC8.unpack (toByteString pem)) <&> Just)
 
 mkBotUserView :: User -> Public.BotUserView
@@ -1167,7 +1167,7 @@ setProviderCookie :: ZAuth.ProviderToken -> Response -> (Handler r) Response
 setProviderCookie t r = do
   s <- view settings
   let hdr = toByteString' (Cookie.renderSetCookie (cookie s))
-  return (addHeader "Set-Cookie" hdr r)
+  pure (addHeader "Set-Cookie" hdr r)
   where
     cookie s =
       Cookie.def
@@ -1180,34 +1180,34 @@ setProviderCookie t r = do
         }
 
 maybeInvalidProvider :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeInvalidProvider = maybe (throwStd invalidProvider) return
+maybeInvalidProvider = maybe (throwStd invalidProvider) pure
 
 maybeInvalidCode :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeInvalidCode = maybe (throwStd (errorToWai @'InvalidCode)) return
+maybeInvalidCode = maybe (throwStd (errorToWai @'InvalidCode)) pure
 
 maybeServiceNotFound :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeServiceNotFound = maybe (throwStd (notFound "Service not found")) return
+maybeServiceNotFound = maybe (throwStd (notFound "Service not found")) pure
 
 maybeProviderNotFound :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeProviderNotFound = maybe (throwStd (notFound "Provider not found")) return
+maybeProviderNotFound = maybe (throwStd (notFound "Provider not found")) pure
 
 maybeConvNotFound :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeConvNotFound = maybe (throwStd (notFound "Conversation not found")) return
+maybeConvNotFound = maybe (throwStd (notFound "Conversation not found")) pure
 
 maybeBadCredentials :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeBadCredentials = maybe (throwStd (errorToWai @'BadCredentials)) return
+maybeBadCredentials = maybe (throwStd (errorToWai @'BadCredentials)) pure
 
 maybeInvalidServiceKey :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeInvalidServiceKey = maybe (throwStd invalidServiceKey) return
+maybeInvalidServiceKey = maybe (throwStd invalidServiceKey) pure
 
 maybeInvalidBot :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeInvalidBot = maybe (throwStd invalidBot) return
+maybeInvalidBot = maybe (throwStd invalidBot) pure
 
 maybeInvalidUser :: Monad m => Maybe a -> (ExceptT Error m) a
-maybeInvalidUser = maybe (throwStd (errorToWai @'InvalidUser)) return
+maybeInvalidUser = maybe (throwStd (errorToWai @'InvalidUser)) pure
 
 rangeChecked :: (Within a n m, Monad monad) => a -> (ExceptT Error monad) (Range n m a)
-rangeChecked = either (throwStd . invalidRange . fromString) return . checkedEither
+rangeChecked = either (throwStd . invalidRange . fromString) pure . checkedEither
 
 invalidServiceKey :: Wai.Error
 invalidServiceKey = Wai.mkError status400 "invalid-service-key" "Invalid service key."
diff --git a/services/brig/src/Brig/Provider/DB.hs b/services/brig/src/Brig/Provider/DB.hs
index d2dc915989..bf14143ddf 100644
--- a/services/brig/src/Brig/Provider/DB.hs
+++ b/services/brig/src/Brig/Provider/DB.hs
@@ -52,7 +52,7 @@ insertAccount ::
 insertAccount name pass url descr = do
   pid <- randomId
   retry x5 $ write cql $ params LocalQuorum (pid, name, pass, url, descr)
-  return pid
+  pure pid
   where
     cql :: PrepQuery W (ProviderId, Name, Password, HttpsUrl, Text) ()
     cql = "INSERT INTO provider (id, name, password, url, descr) VALUES (?, ?, ?, ?, ?)"
@@ -204,7 +204,7 @@ insertService pid name summary descr url token key fprint assets tags = do
       params
         LocalQuorum
         (pid, sid, name, summary, descr, url, [token], [key], [fprint], assets, tagSet, False)
-  return sid
+  pure sid
   where
     cql ::
       PrepQuery
@@ -516,7 +516,7 @@ updateServiceTags ::
   (Name, RangedServiceTags) ->
   BatchM ()
 updateServiceTags pid sid (oldName, oldTags) (newName, newTags)
-  | eqTags && eqNames = return ()
+  | eqTags && eqNames = pure ()
   | eqNames = do
     let name = oldNameLower
     let added = diffTags newTags oldTags
@@ -582,21 +582,21 @@ paginateServiceTags tags start size providerFilter = liftClient $ do
   p <- filterResults providerFilter start' <$> queryAll start' size' tags'
   r <- mapConcurrently resolveRow (result p)
   -- See Note [buggy pagination]
-  return $! ServiceProfilePage (hasMore p) (catMaybes r)
+  pure $! ServiceProfilePage (hasMore p) (catMaybes r)
   where
     start' = maybe "" Text.toLower start
     unpackTags :: QueryAnyTags 1 3 -> [QueryAllTags 1 3]
     unpackTags = Set.toList . fromRange . queryAnyTagsRange
     queryAll :: Text -> Int32 -> [QueryAllTags 1 3] -> Client (Page IndexRow)
-    queryAll _ _ [] = return emptyPage
+    queryAll _ _ [] = pure emptyPage
     queryAll s l [t] = do
       p <- queryTags s l t
-      return $! p {result = trim size (result p)}
+      pure $! p {result = trim size (result p)}
     queryAll s l ts = do
       ps <- mapConcurrently (queryTags s l) ts
       let rows = trim l (unfoldr nextRow (map result ps))
       let more = any hasMore ps || length rows > fromIntegral size
-      return $! emptyPage {hasMore = more, result = trim size rows}
+      pure $! emptyPage {hasMore = more, result = trim size rows}
     nextRow :: [[IndexRow]] -> Maybe (IndexRow, [[IndexRow]])
     nextRow rs = case mapMaybe uncons rs of
       [] -> Nothing
@@ -670,7 +670,7 @@ paginateServiceNames mbPrefix size providerFilter = liftClient $ do
        in filterResults providerFilter prefix' <$> queryPrefixes prefix' size'
   r <- mapConcurrently resolveRow (result p)
   -- See Note [buggy pagination]
-  return $! ServiceProfilePage (hasMore p) (catMaybes r)
+  pure $! ServiceProfilePage (hasMore p) (catMaybes r)
   where
     queryAll len = do
       let cql :: PrepQuery R () IndexRow
@@ -678,7 +678,7 @@ paginateServiceNames mbPrefix size providerFilter = liftClient $ do
             "SELECT name, provider, service \
             \FROM service_prefix"
       p <- retry x1 $ paginate cql $ paramsP One () len
-      return $! p {result = trim size (result p)}
+      pure $! p {result = trim size (result p)}
     queryPrefixes prefix len = do
       let cql :: PrepQuery R (Text, Text) IndexRow
           cql =
@@ -689,7 +689,7 @@ paginateServiceNames mbPrefix size providerFilter = liftClient $ do
         retry x1 $
           paginate cql $
             paramsP One (mkPrefixIndex (Name prefix), prefix) len
-      return $! p {result = trim size (result p)}
+      pure $! p {result = trim size (result p)}
 
 -- Pagination utilities
 filterResults :: Maybe ProviderId -> Text -> Page IndexRow -> Page IndexRow
@@ -705,7 +705,7 @@ filterbyProvider pid p = do
 
 filterPrefix :: Text -> Page IndexRow -> Page IndexRow
 filterPrefix prefix p = do
-  let prefixed = filter (\(Name n, _, _) -> prefix `Text.isPrefixOf` (Text.toLower n)) (result p)
+  let prefixed = filter (\(Name n, _, _) -> prefix `Text.isPrefixOf` Text.toLower n) (result p)
       -- if they were all valid prefixes, there may be more in Cassandra
       allValid = length prefixed == length (result p)
       more = allValid && hasMore p
@@ -795,7 +795,7 @@ paginateServiceWhitelist tid mbPrefix filterDisabled size = liftClient $ do
       . maybeFilterDisabled
       . catMaybes
       <$> mapConcurrently (uncurry lookupServiceProfile) p
-  return
+  pure
     $! ServiceProfilePage
       (length r > fromIntegral size)
       (trim size r)
diff --git a/services/brig/src/Brig/Provider/RPC.hs b/services/brig/src/Brig/Provider/RPC.hs
index 4c5ef88120..2a26239f39 100644
--- a/services/brig/src/Brig/Provider/RPC.hs
+++ b/services/brig/src/Brig/Provider/RPC.hs
@@ -88,7 +88,7 @@ createBot scon new = do
     -- here, not a @Response (Maybe ByteString)@.
     decodeBytes ctx bs = case eitherDecode' bs of
       Left e -> throwM $ ParseException ctx e
-      Right a -> return a
+      Right a -> pure a
     reqBuilder =
       extReq scon ["bots"]
         . method POST
@@ -235,7 +235,7 @@ removeBotMember zusr zcon conv bot = do
   rs <- galleyRequest DELETE req
   if isJust (responseBody rs) && Bilge.statusCode rs == 200
     then Just <$> decodeBody "galley" rs
-    else return Nothing
+    else pure Nothing
   where
     req =
       path "/i/bots"
diff --git a/services/brig/src/Brig/Queue/Stomp.hs b/services/brig/src/Brig/Queue/Stomp.hs
index 6ee788475e..63741dbba0 100644
--- a/services/brig/src/Brig/Queue/Stomp.hs
+++ b/services/brig/src/Brig/Queue/Stomp.hs
@@ -167,7 +167,7 @@ listen b q callback =
         msg (val "Exception when listening to a STOMP queue")
           ~~ field "queue" (show q)
           ~~ field "error" (show e)
-      return True
+      pure True
 
 -- Note [exception handling]
 -- ~~~
diff --git a/services/brig/src/Brig/Run.hs b/services/brig/src/Brig/Run.hs
index 069af57954..a2b87e71a1 100644
--- a/services/brig/src/Brig/Run.hs
+++ b/services/brig/src/Brig/Run.hs
@@ -110,7 +110,7 @@ run o = do
 mkApp :: Opts -> IO (Wai.Application, Env)
 mkApp o = do
   e <- newEnv o
-  return (middleware e $ \reqId -> servantApp (e & requestId .~ reqId), e)
+  pure (middleware e $ \reqId -> servantApp (e & requestId .~ reqId), e)
   where
     rtree :: Tree (App (Handler BrigCanonicalEffects))
     rtree = compile sitemap
diff --git a/services/brig/src/Brig/SMTP.hs b/services/brig/src/Brig/SMTP.hs
index f0b9eccad0..920752199b 100644
--- a/services/brig/src/Brig/SMTP.hs
+++ b/services/brig/src/Brig/SMTP.hs
@@ -73,14 +73,14 @@ initSMTP lg host port credentials connType = do
             SMTP.defaultSettingsSMTPSSL {SMTP.sslPort = p}
       ok <- case credentials of
         (Just (Username u, Password p)) -> SMTP.authenticate SMTP.LOGIN (unpack u) (unpack p) conn
-        _ -> return True
-      return (ok, conn)
+        _ -> pure True
+      pure (ok, conn)
     create = do
       (ok, conn) <- connect
       if ok
         then Logger.log lg Logger.Debug (msg $ val "Established connection to: " +++ host)
         else Logger.log lg Logger.Warn (msg $ val "Failed to established connection, check your credentials to connect to: " +++ host)
-      return conn
+      pure conn
     destroy c = do
       SMTP.closeSMTP c
       Logger.log lg Logger.Debug (msg $ val "Closing connection to: " +++ host)
diff --git a/services/brig/src/Brig/Sem/CodeStore/Cassandra.hs b/services/brig/src/Brig/Sem/CodeStore/Cassandra.hs
index 0aff544c97..7ebc58d057 100644
--- a/services/brig/src/Brig/Sem/CodeStore/Cassandra.hs
+++ b/services/brig/src/Brig/Sem/CodeStore/Cassandra.hs
@@ -85,8 +85,8 @@ genPhoneCode =
 
 mkPwdResetKey :: MonadIO m => UserId -> m PasswordResetKey
 mkPwdResetKey u = do
-  d <- liftIO $ getDigestByName "SHA256" >>= maybe (error "SHA256 not found") return
-  return . PasswordResetKey . encodeBase64Url . digestBS d $ toByteString' u
+  d <- liftIO $ getDigestByName "SHA256" >>= maybe (error "SHA256 not found") pure
+  pure . PasswordResetKey . encodeBase64Url . digestBS d $ toByteString' u
 
 interpretClientToIO ::
   Member (Final IO) r =>
diff --git a/services/brig/src/Brig/Sem/PasswordResetStore/CodeStore.hs b/services/brig/src/Brig/Sem/PasswordResetStore/CodeStore.hs
index b16e51b619..c509f3c3a5 100644
--- a/services/brig/src/Brig/Sem/PasswordResetStore/CodeStore.hs
+++ b/services/brig/src/Brig/Sem/PasswordResetStore/CodeStore.hs
@@ -59,7 +59,7 @@ create u target = do
     key
     (PRQueryData code u (Identity maxAttempts) (Identity (ttl `addUTCTime` now)))
     (round ttl)
-  return (key, code)
+  pure (key, code)
 
 lookup ::
   Members '[CodeStore, Now] r =>
@@ -70,8 +70,8 @@ lookup u = do
   now <- Now.get
   validate now =<< codeSelect key
   where
-    validate now (Just (PRQueryData c _ _ (Just t))) | t > now = return $ Just c
-    validate _ _ = return Nothing
+    validate now (Just (PRQueryData c _ _ (Just t))) | t > now = pure $ Just c
+    validate _ _ = pure Nothing
 
 verify ::
   Members '[CodeStore, Now] r =>
@@ -81,9 +81,9 @@ verify (k, c) = do
   now <- Now.get
   code <- codeSelect k
   case code of
-    Just (PRQueryData c' u _ (Just t)) | c == c' && t >= now -> return (Just u)
+    Just (PRQueryData c' u _ (Just t)) | c == c' && t >= now -> pure (Just u)
     Just (PRQueryData c' u (Just n) (Just t)) | n > 1 && t > now -> do
       codeInsert k (PRQueryData c' u (Identity (n - 1)) (Identity t)) (round ttl)
-      return Nothing
+      pure Nothing
     Just PRQueryData {} -> codeDelete k $> Nothing
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
diff --git a/services/brig/src/Brig/Team/API.hs b/services/brig/src/Brig/Team/API.hs
index 025a926f04..25b63a9e4f 100644
--- a/services/brig/src/Brig/Team/API.hs
+++ b/services/brig/src/Brig/Team/API.hs
@@ -229,7 +229,7 @@ getInvitationCodeH (_ ::: t ::: r) = do
 getInvitationCode :: TeamId -> InvitationId -> (Handler r) FoundInvitationCode
 getInvitationCode t r = do
   code <- lift . wrapClient $ DB.lookupInvitationCode t r
-  maybe (throwStd $ errorToWai @'E.InvalidInvitationCode) (return . FoundInvitationCode) code
+  maybe (throwStd $ errorToWai @'E.InvalidInvitationCode) (pure . FoundInvitationCode) code
 
 newtype FoundInvitationCode = FoundInvitationCode InvitationCode
   deriving (Eq, Show, Generic)
@@ -258,8 +258,8 @@ createInvitationPublic uid tid body = do
   let inviteeRole = fromMaybe Team.defaultRole . irRole $ body
   inviter <- do
     let inviteePerms = Team.rolePermissions inviteeRole
-    idt <- maybe (throwStd (errorToWai @'E.NoIdentity)) return =<< lift (fetchUserIdentity uid)
-    from <- maybe (throwStd noEmail) return (emailIdentity idt)
+    idt <- maybe (throwStd (errorToWai @'E.NoIdentity)) pure =<< lift (fetchUserIdentity uid)
+    from <- maybe (throwStd noEmail) pure (emailIdentity idt)
     ensurePermissionToAddUser uid tid inviteePerms
     pure $ CreateInvitationInviter uid from
 
@@ -322,7 +322,7 @@ createInvitation' tid inviteeRole mbInviterUid fromEmail body = do
   --             sendActivationCode. Refactor this to a single place
 
   -- Validate e-mail
-  inviteeEmail <- either (const $ throwStd (errorToWai @'E.InvalidEmail)) return (Email.validateEmail (irInviteeEmail body))
+  inviteeEmail <- either (const $ throwStd (errorToWai @'E.InvalidEmail)) pure (Email.validateEmail (irInviteeEmail body))
   let uke = userEmailKey inviteeEmail
   blacklistedEm <- lift $ wrapClient $ Blacklist.exists uke
   when blacklistedEm $
@@ -333,7 +333,7 @@ createInvitation' tid inviteeRole mbInviterUid fromEmail body = do
 
   -- Validate phone
   inviteePhone <- for (irInviteePhone body) $ \p -> do
-    validatedPhone <- maybe (throwStd (errorToWai @'E.InvalidPhone)) return =<< lift (wrapClient $ Phone.validatePhone p)
+    validatedPhone <- maybe (throwStd (errorToWai @'E.InvalidPhone)) pure =<< lift (wrapClient $ Phone.validatePhone p)
     let ukp = userPhoneKey validatedPhone
     blacklistedPh <- lift $ wrapClient $ Blacklist.exists ukp
     when blacklistedPh $
@@ -341,7 +341,7 @@ createInvitation' tid inviteeRole mbInviterUid fromEmail body = do
     phoneTaken <- lift $ isJust <$> wrapClient (Data.lookupKey ukp)
     when phoneTaken $
       throwStd phoneExists
-    return validatedPhone
+    pure validatedPhone
   maxSize <- setMaxTeamSize <$> view settings
   pending <- lift $ wrapClient $ DB.countInvitations tid
   when (fromIntegral pending >= maxSize) $
@@ -385,12 +385,12 @@ listInvitations :: UserId -> TeamId -> Maybe InvitationId -> Range 1 500 Int32 -
 listInvitations uid tid start size = do
   ensurePermissions uid tid [Team.AddTeamMember]
   rs <- lift $ wrapClient $ DB.lookupInvitations tid start size
-  return $! Public.InvitationList (DB.resultList rs) (DB.resultHasMore rs)
+  pure $! Public.InvitationList (DB.resultList rs) (DB.resultHasMore rs)
 
 getInvitationH :: JSON ::: UserId ::: TeamId ::: InvitationId -> (Handler r) Response
 getInvitationH (_ ::: uid ::: tid ::: iid) = do
   inv <- getInvitation uid tid iid
-  return $ case inv of
+  pure $ case inv of
     Just i -> json i
     Nothing -> setStatus status404 empty
 
@@ -406,12 +406,12 @@ getInvitationByCodeH (_ ::: c) = do
 getInvitationByCode :: Public.InvitationCode -> (Handler r) Public.Invitation
 getInvitationByCode c = do
   inv <- lift . wrapClient $ DB.lookupInvitationByCode c
-  maybe (throwStd $ errorToWai @'E.InvalidInvitationCode) return inv
+  maybe (throwStd $ errorToWai @'E.InvalidInvitationCode) pure inv
 
 headInvitationByEmailH :: JSON ::: Email -> (Handler r) Response
 headInvitationByEmailH (_ ::: e) = do
   inv <- lift $ wrapClient $ DB.lookupInvitationInfoByEmail e
-  return $ case inv of
+  pure $ case inv of
     DB.InvitationByEmail _ -> setStatus status200 empty
     DB.InvitationByEmailNotFound -> setStatus status404 empty
     DB.InvitationByEmailMoreThanOne -> setStatus status409 empty
@@ -426,7 +426,7 @@ getInvitationByEmailH (_ ::: email) =
 getInvitationByEmail :: Email -> (Handler r) Public.Invitation
 getInvitationByEmail email = do
   inv <- lift $ wrapClient $ DB.lookupInvitationByEmail email
-  maybe (throwStd (notFound "Invitation not found")) return inv
+  maybe (throwStd (notFound "Invitation not found")) pure inv
 
 suspendTeamH :: JSON ::: TeamId -> (Handler r) Response
 suspendTeamH (_ ::: tid) = do
@@ -458,5 +458,5 @@ changeTeamAccountStatuses tid s = do
   uids <- toList1 =<< lift (fmap (view Team.userId) . view Team.teamMembers <$> wrapHttp (Intra.getTeamMembers tid))
   wrapHttpClientE (API.changeAccountStatus uids s) !>> accountStatusError
   where
-    toList1 (x : xs) = return $ List1.list1 x xs
+    toList1 (x : xs) = pure $ List1.list1 x xs
     toList1 [] = throwStd (notFound "Team not found or no members")
diff --git a/services/brig/src/Brig/Team/DB.hs b/services/brig/src/Brig/Team/DB.hs
index 920abedd76..6a28ec19b8 100644
--- a/services/brig/src/Brig/Team/DB.hs
+++ b/services/brig/src/Brig/Team/DB.hs
@@ -99,7 +99,7 @@ insertInvitation iid t role (toUTCTimeMillis -> now) minviter email inviteeName
     addPrepQuery cqlInvitation (t, role, iid, code, email, now, minviter, inviteeName, phone, round timeout)
     addPrepQuery cqlInvitationInfo (code, t, iid, round timeout)
     addPrepQuery cqlInvitationByEmail (email, t, iid, code, round timeout)
-  return (inv, code)
+  pure (inv, code)
   where
     cqlInvitationInfo :: PrepQuery W (InvitationCode, TeamId, InvitationId, Int32) ()
     cqlInvitationInfo = "INSERT INTO team_invitation_info (code, team, id) VALUES (?, ?, ?) USING TTL ?"
@@ -121,7 +121,7 @@ lookupInvitationByCode :: MonadClient m => InvitationCode -> m (Maybe Invitation
 lookupInvitationByCode i =
   lookupInvitationInfo i >>= \case
     Just InvitationInfo {..} -> lookupInvitation iiTeam iiInvId
-    _ -> return Nothing
+    _ -> pure Nothing
 
 lookupInvitationCode :: MonadClient m => TeamId -> InvitationId -> m (Maybe InvitationCode)
 lookupInvitationCode t r =
@@ -142,7 +142,7 @@ lookupInvitations team start (fromRange -> size) = do
   page <- case start of
     Just ref -> retry x1 $ paginate cqlSelectFrom (paramsP LocalQuorum (team, ref) (size + 1))
     Nothing -> retry x1 $ paginate cqlSelect (paramsP LocalQuorum (Identity team) (size + 1))
-  return $ toResult (hasMore page) $ map toInvitation (trim page)
+  pure $ toResult (hasMore page) $ map toInvitation (trim page)
   where
     trim p = take (fromIntegral size) (result p)
     toResult more invs =
@@ -188,7 +188,7 @@ deleteInvitations t =
 
 lookupInvitationInfo :: MonadClient m => InvitationCode -> m (Maybe InvitationInfo)
 lookupInvitationInfo ic@(InvitationCode c)
-  | c == mempty = return Nothing
+  | c == mempty = pure Nothing
   | otherwise =
     fmap (toInvitationInfo ic)
       <$> retry x1 (query1 cqlInvitationInfo (params LocalQuorum (Identity ic)))
@@ -201,29 +201,29 @@ lookupInvitationByEmail :: (Log.MonadLogger m, MonadClient m) => Email -> m (May
 lookupInvitationByEmail e =
   lookupInvitationInfoByEmail e >>= \case
     InvitationByEmail InvitationInfo {..} -> lookupInvitation iiTeam iiInvId
-    _ -> return Nothing
+    _ -> pure Nothing
 
 lookupInvitationInfoByEmail :: (Log.MonadLogger m, MonadClient m) => Email -> m InvitationByEmail
 lookupInvitationInfoByEmail email = do
   res <- retry x1 (query cqlInvitationEmail (params LocalQuorum (Identity email)))
   case res of
-    [] -> return InvitationByEmailNotFound
-    (tid, invId, code) : [] ->
+    [] -> pure InvitationByEmailNotFound
+    [(tid, invId, code)] ->
       -- one invite pending
-      return $ InvitationByEmail (InvitationInfo code tid invId)
+      pure $ InvitationByEmail (InvitationInfo code tid invId)
     _ : _ : _ -> do
       -- edge case: more than one pending invite from different teams
       Log.info $
         Log.msg (Log.val "team_invidation_email: multiple pending invites from different teams for the same email")
           Log.~~ Log.field "email" (show email)
-      return InvitationByEmailMoreThanOne
+      pure InvitationByEmailMoreThanOne
   where
     cqlInvitationEmail :: PrepQuery R (Identity Email) (TeamId, InvitationId, InvitationCode)
     cqlInvitationEmail = "SELECT team, invitation, code FROM team_invitation_email WHERE email = ?"
 
 countInvitations :: MonadClient m => TeamId -> m Int64
 countInvitations t =
-  fromMaybe 0 . fmap runIdentity
+  maybe 0 runIdentity
     <$> retry x1 (query1 cqlSelect (params LocalQuorum (Identity t)))
   where
     cqlSelect :: PrepQuery R (Identity TeamId) (Identity Int64)
diff --git a/services/brig/src/Brig/Unique.hs b/services/brig/src/Brig/Unique.hs
index c30884ca10..88e325e8c4 100644
--- a/services/brig/src/Brig/Unique.hs
+++ b/services/brig/src/Brig/Unique.hs
@@ -61,7 +61,7 @@ withClaim u v t io = do
   case claims of
     [] -> claim -- Free
     [u'] | u == u' -> claim -- Claimed by 'u' (retries are allowed).
-    _ -> return Nothing -- Conflicting claims, TTL must expire.
+    _ -> pure Nothing -- Conflicting claims, TTL must expire.
   where
     -- [Note: Guarantees]
     claim = do
@@ -70,7 +70,7 @@ withClaim u v t io = do
       claimed <- (== [u]) <$> lookupClaims v
       if claimed
         then liftIO $ timeout (fromIntegral ttl # Second) io
-        else return Nothing
+        else pure Nothing
     cql :: PrepQuery W (Int32, C.Set (Id a), Text) ()
     cql = "UPDATE unique_claims USING TTL ? SET claims = claims + ? WHERE value = ?"
 
diff --git a/services/brig/src/Brig/User/API/Auth.hs b/services/brig/src/Brig/User/API/Auth.hs
index 757aba32a8..daa60d91f2 100644
--- a/services/brig/src/Brig/User/API/Auth.hs
+++ b/services/brig/src/Brig/User/API/Auth.hs
@@ -219,7 +219,7 @@ sendLoginCode :: Public.SendLoginCode -> (Handler r) Public.LoginCodeTimeout
 sendLoginCode (Public.SendLoginCode phone call force) = do
   checkWhitelist (Right phone)
   c <- wrapClientE (Auth.sendLoginCode phone call force) !>> sendLoginCodeError
-  return $ Public.LoginCodeTimeout (pendingLoginTimeout c)
+  pure $ Public.LoginCodeTimeout (pendingLoginTimeout c)
 
 getLoginCodeH :: JSON ::: Phone -> (Handler r) Response
 getLoginCodeH (_ ::: phone) = json <$> getLoginCode phone
@@ -227,12 +227,12 @@ getLoginCodeH (_ ::: phone) = json <$> getLoginCode phone
 getLoginCode :: Phone -> (Handler r) Public.PendingLoginCode
 getLoginCode phone = do
   code <- lift $ wrapClient $ Auth.lookupLoginCode phone
-  maybe (throwStd loginCodeNotFound) return code
+  maybe (throwStd loginCodeNotFound) pure code
 
 reAuthUserH :: UserId ::: JsonRequest ReAuthUser -> (Handler r) Response
 reAuthUserH (uid ::: req) = do
   reAuthUser uid =<< parseJsonBody req
-  return empty
+  pure empty
 
 reAuthUser :: UserId -> ReAuthUser -> (Handler r) ()
 reAuthUser uid body = do
@@ -401,7 +401,7 @@ tokenRequest = opt (userToken ||| legalHoldUserToken) .&. opt (accessToken ||| l
     bearer (Okay _ b) =
       let (prefix, suffix) = BS.splitAt 7 b
        in if prefix == "Bearer "
-            then return suffix
+            then pure suffix
             else
               Fail
                 ( setReason
@@ -419,7 +419,7 @@ tokenRequest = opt (userToken ||| legalHoldUserToken) .&. opt (accessToken ||| l
               TypeError
               (setMessage "Invalid access token" (err status403))
           )
-      Just t -> return t
+      Just t -> pure t
 
 tokenResponse :: ZAuth.UserTokenLike u => Auth.Access u -> (AppT r) Response
 tokenResponse (Auth.Access t Nothing) = pure $ json t
@@ -438,7 +438,7 @@ cookies k r =
     cc ->
       case mapMaybe fromByteString cc of
         [] -> Fail . addLabel "cookie" . typeError k $ "Failed to get zuid cookies"
-        (x : xs) -> return $ List1.list1 x xs
+        (x : xs) -> pure $ List1.list1 x xs
 
 notAvailable :: ByteString -> P.Error
 notAvailable k = e400 & setReason NotAvailable . setSource k
diff --git a/services/brig/src/Brig/User/API/Handle.hs b/services/brig/src/Brig/User/API/Handle.hs
index 3f40f8767c..db71c04406 100644
--- a/services/brig/src/Brig/User/API/Handle.hs
+++ b/services/brig/src/Brig/User/API/Handle.hs
@@ -63,12 +63,12 @@ getLocalHandleInfo self handle = do
   lift . Log.info $ Log.msg $ Log.val "getHandleInfo - local lookup"
   maybeOwnerId <- lift . wrapClient $ API.lookupHandle handle
   case maybeOwnerId of
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
     Just ownerId -> do
       domain <- viewFederationDomain
       ownerProfile <- wrapHttpClientE (API.lookupProfile self (Qualified ownerId domain)) !>> fedError
       owner <- filterHandleResults self (maybeToList ownerProfile)
-      return $ listToMaybe owner
+      pure $ listToMaybe owner
 
 -- | Checks search permissions and filters accordingly
 filterHandleResults :: Local UserId -> [Public.UserProfile] -> (Handler r) [Public.UserProfile]
@@ -77,10 +77,10 @@ filterHandleResults searchingUser us = do
   if sameTeamSearchOnly
     then do
       fromTeam <- lift . wrapClient $ Data.lookupUserTeam (tUnqualified searchingUser)
-      return $ case fromTeam of
+      pure $ case fromTeam of
         Just team -> filter (\x -> Public.profileTeam x == Just team) us
         Nothing -> us
-    else return us
+    else pure us
 
 contactFromProfile :: Public.UserProfile -> Public.Contact
 contactFromProfile profile =
diff --git a/services/brig/src/Brig/User/API/Search.hs b/services/brig/src/Brig/User/API/Search.hs
index 41dbeb51b1..50ab3490aa 100644
--- a/services/brig/src/Brig/User/API/Search.hs
+++ b/services/brig/src/Brig/User/API/Search.hs
@@ -180,11 +180,11 @@ searchLocally searcherId searchTerm maybeMaxResults = do
     mkTeamSearchInfo searcherTeamId = lift $ do
       sameTeamSearchOnly <- fromMaybe False <$> view (settings . Opts.searchSameTeamOnly)
       case searcherTeamId of
-        Nothing -> return Search.NoTeam
+        Nothing -> pure Search.NoTeam
         Just t ->
           -- This flag in brig overrules any flag on galley - it is system wide
           if sameTeamSearchOnly
-            then return (Search.TeamOnly t)
+            then pure (Search.TeamOnly t)
             else do
               -- For team users, we need to check the visibility flag
               handleTeamVisibility t <$> wrapHttp (Intra.getTeamSearchVisibility t)
diff --git a/services/brig/src/Brig/User/Auth.hs b/services/brig/src/Brig/User/Auth.hs
index 35be4024b8..a649fc9fcd 100644
--- a/services/brig/src/Brig/User/Auth.hs
+++ b/services/brig/src/Brig/User/Auth.hs
@@ -100,7 +100,7 @@ sendLoginCode phone call force = do
   pk <-
     maybe
       (throwE $ SendLoginInvalidPhone phone)
-      (return . userPhoneKey)
+      (pure . userPhoneKey)
       =<< lift (validatePhone phone)
   user <- lift $ Data.lookupKey pk
   case user of
@@ -117,7 +117,7 @@ sendLoginCode phone call force = do
           if call
             then sendLoginCall ph (pendingLoginCode c) l
             else sendLoginSms ph (pendingLoginCode c) l
-        return c
+        pure c
 
 lookupLoginCode ::
   ( MonadClient m,
@@ -128,7 +128,7 @@ lookupLoginCode ::
   m (Maybe PendingLoginCode)
 lookupLoginCode phone =
   Data.lookupKey (userPhoneKey phone) >>= \case
-    Nothing -> return Nothing
+    Nothing -> pure Nothing
     Just u -> do
       Log.debug $ field "user" (toByteString u) . field "action" (Log.val "User.lookupLoginCode")
       Data.lookupLoginCode u
@@ -277,7 +277,7 @@ renewAccess uts at = do
   catchSuspendInactiveUser uid ZAuth.Expired
   ck' <- lift $ nextCookie ck
   at' <- lift $ newAccessToken (fromMaybe ck ck') at
-  return $ Access at' ck'
+  pure $ Access at' ck'
 
 revokeAccess ::
   (MonadClient m, Log.MonadLogger m) =>
@@ -348,7 +348,7 @@ newAccess uid ct cl = do
     Left delay -> throwE $ LoginThrottled delay
     Right ck -> do
       t <- lift $ newAccessToken @u @a ck Nothing
-      return $ Access t (Just ck)
+      pure $ Access t (Just ck)
 
 resolveLoginId :: (MonadClient m, MonadReader Env m) => LoginId -> ExceptT LoginError m UserId
 resolveLoginId li = do
@@ -360,32 +360,32 @@ resolveLoginId li = do
         if pending
           then LoginPendingActivation
           else LoginFailed
-    Just uid -> return uid
+    Just uid -> pure uid
 
 validateLoginId :: (MonadClient m, MonadReader Env m) => LoginId -> ExceptT LoginError m (Either UserKey Handle)
 validateLoginId (LoginByEmail email) =
   either
     (const $ throwE LoginFailed)
-    (return . Left . userEmailKey)
+    (pure . Left . userEmailKey)
     (validateEmail email)
 validateLoginId (LoginByPhone phone) =
   maybe
     (throwE LoginFailed)
-    (return . Left . userPhoneKey)
+    (pure . Left . userPhoneKey)
     =<< lift (validatePhone phone)
 validateLoginId (LoginByHandle h) =
-  return (Right h)
+  pure (Right h)
 
 isPendingActivation :: (MonadClient m, MonadReader Env m) => LoginId -> m Bool
 isPendingActivation ident = case ident of
-  (LoginByHandle _) -> return False
+  (LoginByHandle _) -> pure False
   (LoginByEmail e) -> checkKey (userEmailKey e)
   (LoginByPhone p) -> checkKey (userPhoneKey p)
   where
     checkKey k = do
       usr <- (>>= fst) <$> Data.lookupActivationCode k
       case usr of
-        Nothing -> return False
+        Nothing -> pure False
         Just u -> maybe False (checkAccount k) <$> Data.lookupAccount u
     checkAccount k a =
       let i = userIdentity (accountUser a)
@@ -421,7 +421,7 @@ validateTokens uts at = do
       List1 (Either ZAuth.Failure (UserId, Cookie (ZAuth.Token u))) ->
       ExceptT ZAuth.Failure m (UserId, Cookie (ZAuth.Token u))
     getFirstSuccessOrFirstFail tks = case (lefts $ NE.toList $ List1.toNonEmpty tks, rights $ NE.toList $ List1.toNonEmpty tks) of
-      (_, suc : _) -> return suc
+      (_, suc : _) -> pure suc
       (e : _, _) -> throwE e
       _ -> throwE ZAuth.Invalid -- Impossible
 
@@ -442,8 +442,8 @@ validateToken ut at = do
     ExceptT (ZAuth.validateToken token)
       `catchE` \e ->
         unless (e == ZAuth.Expired) (throwE e)
-  ck <- lift (lookupCookie ut) >>= maybe (throwE ZAuth.Invalid) return
-  return (ZAuth.userTokenOf ut, ck)
+  ck <- lift (lookupCookie ut) >>= maybe (throwE ZAuth.Invalid) pure
+  pure (ZAuth.userTokenOf ut, ck)
 
 -- | Allow to login as any user without having the credentials.
 ssoLogin ::
diff --git a/services/brig/src/Brig/User/Auth/Cookie.hs b/services/brig/src/Brig/User/Auth/Cookie.hs
index 222a78422e..461f136a3c 100644
--- a/services/brig/src/Brig/User/Auth/Cookie.hs
+++ b/services/brig/src/Brig/User/Auth/Cookie.hs
@@ -95,7 +95,7 @@ newCookie uid typ label = do
             cookieValue = tok
           }
   DB.insertCookie uid c Nothing
-  return c
+  pure c
 
 -- | Renew the given cookie with a fresh token, if its age
 -- exceeds the configured minimum threshold.
@@ -119,7 +119,7 @@ nextCookie c = do
   -- a different zauth key index, regardless of age.
   if persist c && diffUTCTime now created > renewAge
     then Just <$> getNext
-    else return Nothing
+    else pure Nothing
   where
     persist = (PersistentCookie ==) . cookieType
     getNext = case cookieSucc c of
@@ -132,7 +132,7 @@ nextCookie c = do
           Nothing -> renewCookie c
           Just c' -> do
             t <- ZAuth.mkUserToken uid (cookieIdNum ck) (cookieExpires c')
-            return c' {cookieValue = t}
+            pure c' {cookieValue = t}
 
 -- | Renew the given cookie with a fresh token.
 renewCookie ::
@@ -154,7 +154,7 @@ renewCookie old = do
   let old' = old {cookieSucc = Just (cookieId new)}
   ttl <- setUserCookieRenewAge <$> view settings
   DB.insertCookie uid old' (Just (DB.TTL (fromIntegral ttl)))
-  return new
+  pure new
 
 -- | Whether a user has not renewed any of her cookies for longer than
 -- 'suspendCookiesOlderThanSecs'.  Call this always before 'newCookie', 'nextCookie',
@@ -189,7 +189,7 @@ newAccessToken c mt = do
     Just t -> ZAuth.renewAccessToken t
   zSettings <- view (zauthEnv . ZAuth.settings)
   let ttl = view (ZAuth.settingsTTL (Proxy @a)) zSettings
-  return $
+  pure $
     bearerToken
       (ZAuth.accessTokenOf t')
       (toByteString t')
@@ -248,7 +248,7 @@ newCookieLimited u typ label = do
   if null evict
     then Right <$> newCookie u typ label
     else case throttleCookies now thr cs of
-      Just wait -> return (Left wait)
+      Just wait -> pure (Left wait)
       Nothing -> do
         revokeCookies u evict []
         Right <$> newCookie u typ label
@@ -263,7 +263,7 @@ setResponseCookie ::
   m Response
 setResponseCookie c r = do
   hdr <- toByteString' . WebCookie.renderSetCookie <$> toWebCookie c
-  return (addHeader "Set-Cookie" hdr r)
+  pure (addHeader "Set-Cookie" hdr r)
 
 toWebCookie :: (Monad m, MonadReader Env m, ZAuth.UserTokenLike u) => Cookie (ZAuth.Token u) -> m WebCookie.SetCookie
 toWebCookie c = do
diff --git a/services/brig/src/Brig/User/Auth/DB/Instances.hs b/services/brig/src/Brig/User/Auth/DB/Instances.hs
index 9e4e60436b..a724bf1bcf 100644
--- a/services/brig/src/Brig/User/Auth/DB/Instances.hs
+++ b/services/brig/src/Brig/User/Auth/DB/Instances.hs
@@ -39,7 +39,7 @@ instance Cql CookieId where
   ctype = Tagged BigIntColumn
   toCql = CqlBigInt . fromIntegral . cookieIdNum
 
-  fromCql (CqlBigInt i) = return (CookieId (fromIntegral i))
+  fromCql (CqlBigInt i) = pure (CookieId (fromIntegral i))
   fromCql _ = Left "fromCql: invalid cookie id"
 
 instance Cql CookieType where
@@ -48,6 +48,6 @@ instance Cql CookieType where
   toCql SessionCookie = CqlInt 0
   toCql PersistentCookie = CqlInt 1
 
-  fromCql (CqlInt 0) = return SessionCookie
-  fromCql (CqlInt 1) = return PersistentCookie
+  fromCql (CqlInt 0) = pure SessionCookie
+  fromCql (CqlInt 1) = pure PersistentCookie
   fromCql _ = Left "fromCql: invalid cookie type"
diff --git a/services/brig/src/Brig/User/Handle.hs b/services/brig/src/Brig/User/Handle.hs
index 1cee4911a8..245679ae51 100644
--- a/services/brig/src/Brig/User/Handle.hs
+++ b/services/brig/src/Brig/User/Handle.hs
@@ -39,7 +39,7 @@ claimHandle uid oldHandle newHandle =
   isJust <$> do
     owner <- lookupHandle newHandle
     case owner of
-      Just uid' | uid /= uid' -> return Nothing
+      Just uid' | uid /= uid' -> pure Nothing
       _ -> do
         env <- ask
         let key = "@" <> fromHandle newHandle
@@ -53,7 +53,7 @@ claimHandle uid oldHandle newHandle =
               -- Free old handle (if it changed)
               for_ (mfilter (/= newHandle) oldHandle) $
                 wrapClient . freeHandle uid
-              return result
+              pure result
 
 -- | Free a 'Handle', making it available to be claimed again.
 freeHandle :: MonadClient m => UserId -> Handle -> m ()
diff --git a/services/brig/src/Brig/User/Search/Index.hs b/services/brig/src/Brig/User/Search/Index.hs
index bee7ad759f..1211c5ff8d 100644
--- a/services/brig/src/Brig/User/Search/Index.hs
+++ b/services/brig/src/Brig/User/Search/Index.hs
@@ -384,7 +384,7 @@ resetIndex ciSettings = liftIndexIO $ do
   gone <-
     ES.indexExists idx >>= \case
       True -> ES.isSuccess <$> traceES "Delete Index" (ES.deleteIndex idx)
-      False -> return True
+      False -> pure True
   if gone
     then createIndex ciSettings
     else throwM (IndexError "Index deletion failed.")
@@ -432,7 +432,7 @@ traceES descr act = liftIndexIO $ do
   info (msg descr)
   r <- act
   info . msg $ (r & statusCode . responseStatus) +++ val " - " +++ responseBody r
-  return r
+  pure r
 
 -- | This mapping defines how elasticsearch will treat each field in a document. Here
 -- is how it treats each field:
@@ -865,18 +865,16 @@ reindexRowToIndexUser
       version :: [Maybe (Writetime Name)] -> m IndexVersion
       version = mkIndexVersion . getMax . mconcat . fmap Max . catMaybes
       shouldIndex =
-        and
-          [ case status of
-              Nothing -> True
-              Just Active -> True
-              Just Suspended -> True
-              Just Deleted -> False
-              Just Ephemeral -> False
-              Just PendingInvitation -> False,
-            activated, -- FUTUREWORK: how is this adding to the first case?
-            isNothing service
-          ]
-
+        ( case status of
+            Nothing -> True
+            Just Active -> True
+            Just Suspended -> True
+            Just Deleted -> False
+            Just Ephemeral -> False
+            Just PendingInvitation -> False
+        )
+          && activated -- FUTUREWORK: how is this adding to the first case?
+          && isNothing service
       idpUrl :: UserSSOId -> Maybe Text
       idpUrl (UserSSOId (SAML.UserRef (SAML.Issuer uri) _subject)) =
         Just $ fromUri uri
@@ -928,7 +926,7 @@ getTeamSearchVisibilityInboundMulti tids = do
           res <- try $ RPC.httpLbs rq id
           case res of
             Left x -> throwM $ RPCException nm rq x
-            Right x -> return x
+            Right x -> pure x
       where
         mkEndpoint service = RPC.host (encodeUtf8 (service ^. epHost)) . RPC.port (service ^. epPort) $ RPC.empty
 
diff --git a/services/brig/src/Brig/User/Search/SearchIndex.hs b/services/brig/src/Brig/User/Search/SearchIndex.hs
index f25ce87680..8f18d0d659 100644
--- a/services/brig/src/Brig/User/Search/SearchIndex.hs
+++ b/services/brig/src/Brig/User/Search/SearchIndex.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE RecordWildCards #-}
 {-# LANGUAGE StrictData #-}
 
diff --git a/services/brig/src/Brig/User/Search/TeamSize.hs b/services/brig/src/Brig/User/Search/TeamSize.hs
index b26d7286f0..2949c8e2fc 100644
--- a/services/brig/src/Brig/User/Search/TeamSize.hs
+++ b/services/brig/src/Brig/User/Search/TeamSize.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE StrictData #-}
 
 -- This file is part of the Wire Server implementation.
diff --git a/services/brig/src/Brig/Whitelist.hs b/services/brig/src/Brig/Whitelist.hs
index 1e2beeb4da..5dc27a352b 100644
--- a/services/brig/src/Brig/Whitelist.hs
+++ b/services/brig/src/Brig/Whitelist.hs
@@ -55,13 +55,13 @@ instance FromJSON Whitelist
 verify :: (MonadIO m, MonadMask m, MonadHttp m) => Whitelist -> Either Email Phone -> m Bool
 verify (Whitelist url user pass) key =
   if isKnownDomain key
-    then return True
+    then pure True
     else recovering x3 httpHandlers . const $ do
       rq <- parseRequest $ unpack url
       rsp <- get' rq $ req (encodeUtf8 user) (encodeUtf8 pass)
       case statusCode rsp of
-        200 -> return True
-        404 -> return False
+        200 -> pure True
+        404 -> pure False
         _ ->
           throwM $
             HttpExceptionRequest rq (StatusCodeException (rsp {responseBody = ()}) mempty)
diff --git a/services/brig/src/Brig/ZAuth.hs b/services/brig/src/Brig/ZAuth.hs
index a7ba3d520f..e5579aa1cd 100644
--- a/services/brig/src/Brig/ZAuth.hs
+++ b/services/brig/src/Brig/ZAuth.hs
@@ -237,7 +237,7 @@ mkEnv :: NonEmpty SecretKey -> NonEmpty PublicKey -> Settings -> IO Env
 mkEnv sk pk sets = do
   zc <- ZC.mkEnv (NonEmpty.head sk) (NonEmpty.tail sk)
   let zv = ZV.mkEnv (NonEmpty.head pk) (NonEmpty.tail pk)
-  return $! Env zc zv sets
+  pure $! Env zc zv sets
 
 class (UserTokenLike u, AccessTokenLike a) => TokenPair u a where
   newAccessToken :: MonadZAuth m => Token u -> m (Token a)
diff --git a/services/brig/test/integration/API/Calling.hs b/services/brig/test/integration/API/Calling.hs
index d6df765201..bc09a07712 100644
--- a/services/brig/test/integration/API/Calling.hs
+++ b/services/brig/test/integration/API/Calling.hs
@@ -46,7 +46,7 @@ import Wire.API.Call.Config
 
 tests :: Manager -> Brig -> Opts.Opts -> FilePath -> FilePath -> IO TestTree
 tests m b opts turn turnV2 = do
-  return $
+  pure $
     testGroup "calling" $
       [ testGroup "turn" $
           [ test m "basic /calls/config - 200" $ testCallsConfig b,
@@ -253,7 +253,7 @@ toTurnURILegacy :: ByteString -> Port -> TurnURI
 toTurnURILegacy h p = toTurnURI SchemeTurn h p Nothing
 
 toTurnURI :: Scheme -> ByteString -> Port -> Maybe Transport -> TurnURI
-toTurnURI s h p t = turnURI s ip p t
+toTurnURI s h = turnURI s ip
   where
     ip =
       fromMaybe (error "Failed to parse host address") $
diff --git a/services/brig/test/integration/API/Federation.hs b/services/brig/test/integration/API/Federation.hs
index f099586e80..74612a2919 100644
--- a/services/brig/test/integration/API/Federation.hs
+++ b/services/brig/test/integration/API/Federation.hs
@@ -61,7 +61,7 @@ import Wire.API.UserMap (UserMap (UserMap))
 -- Note: POST /federation/send-connection-action is implicitly tested in API.User.Connection
 tests :: Manager -> Opt.Opts -> Brig -> Cannon -> FedClient 'Brig -> IO TestTree
 tests m opts brig cannon fedBrigClient =
-  return $
+  pure $
     testGroup
       "federation"
       [ test m "POST /federation/search-users : Found" (testSearchSuccess opts brig),
diff --git a/services/brig/test/integration/API/Internal.hs b/services/brig/test/integration/API/Internal.hs
index 3ec78c59df..6d4ab3f1a7 100644
--- a/services/brig/test/integration/API/Internal.hs
+++ b/services/brig/test/integration/API/Internal.hs
@@ -56,7 +56,7 @@ import qualified Wire.API.Team.Member as Team
 
 tests :: Opt.Opts -> Manager -> Cass.ClientState -> Brig -> Endpoint -> Gundeck -> Galley -> IO TestTree
 tests opts mgr db brig brigep gundeck galley = do
-  return $
+  pure $
     testGroup "api/internal" $
       [ test mgr "ejpd requests" $ testEJPDRequest mgr brig brigep gundeck,
         test mgr "account features: conferenceCalling" $
@@ -244,7 +244,7 @@ keyPackageCreate brig = do
     Nothing -> liftIO $ assertFailure "Claim response empty"
     Just bundle -> case toList $ kpbEntries bundle of
       [] -> liftIO $ assertFailure "Claim response held no bundles"
-      (h : _) -> return $ kpbeRef h
+      (h : _) -> pure $ kpbeRef h
 
 kpcPut :: HasCallStack => Brig -> KeyPackageRef -> Qualified ConvId -> Http ()
 kpcPut brig ref qConv = do
@@ -262,8 +262,8 @@ kpcGet brig ref = do
   resp <-
     get (brig . paths ["i", "mls", "key-packages", toByteString' $ toUrlPiece ref, "conversation"])
   liftIO $ case statusCode resp of
-    404 -> return Nothing
-    200 -> return $ responseBody resp >>= decode
+    404 -> pure Nothing
+    200 -> pure $ responseBody resp >>= decode
     _ -> assertFailure "GET i/mls/key-packages/:ref/conversation failed"
 
 testKpcFreshGet :: Brig -> Http ()
diff --git a/services/brig/test/integration/API/Internal/Util.hs b/services/brig/test/integration/API/Internal/Util.hs
index b526990ab6..06e0c4832d 100644
--- a/services/brig/test/integration/API/Internal/Util.hs
+++ b/services/brig/test/integration/API/Internal/Util.hs
@@ -113,8 +113,8 @@ scaffolding brig gundeck = do
     randomToken :: MonadIO m => m PushToken.PushToken
     randomToken = liftIO $ do
       c <- liftIO $ newClientId <$> (randomIO :: IO Word64)
-      tok <- PushToken.Token . T.decodeUtf8 <$> B16.encode <$> randomBytes 32
-      return $ PushToken.pushToken PushToken.APNSSandbox (PushToken.AppName "test") tok c
+      tok <- (PushToken.Token . T.decodeUtf8) . B16.encode <$> randomBytes 32
+      pure $ PushToken.pushToken PushToken.APNSSandbox (PushToken.AppName "test") tok c
 
 ejpdRequestClientM :: Maybe Bool -> EJPDRequestBody -> Client.ClientM EJPDResponseBody
 ejpdRequestClientM = Client.client (Proxy @("i" :> IAPI.EJPDRequest))
diff --git a/services/brig/test/integration/API/MLS.hs b/services/brig/test/integration/API/MLS.hs
index 7f66272578..0fefc518e3 100644
--- a/services/brig/test/integration/API/MLS.hs
+++ b/services/brig/test/integration/API/MLS.hs
@@ -166,9 +166,7 @@ testKeyPackageRemoteClaim opts brig = do
     liftIO . replicateM 2 . generate $
       -- claimed key packages are not validated by the backend, so it is fine to
       -- make up some random data here
-      KeyPackageBundleEntry
-        <$> pure u
-        <*> arbitrary
+      KeyPackageBundleEntry u <$> arbitrary
         <*> (KeyPackageRef . BS.pack <$> vector 32)
         <*> (KeyPackageData . BS.pack <$> vector 64)
   let mockBundle = KeyPackageBundle (Set.fromList entries)
diff --git a/services/brig/test/integration/API/Metrics.hs b/services/brig/test/integration/API/Metrics.hs
index 4153a016b0..fa735a391c 100644
--- a/services/brig/test/integration/API/Metrics.hs
+++ b/services/brig/test/integration/API/Metrics.hs
@@ -1,8 +1,5 @@
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TupleSections #-}
-{-# LANGUAGE ViewPatterns #-}
 
 -- This file is part of the Wire Server implementation.
 --
@@ -39,7 +36,7 @@ import Util
 
 tests :: Manager -> Brig -> IO TestTree
 tests manager brig = do
-  return $
+  pure $
     testGroup
       "metrics"
       [ testCase "prometheus" . void $ runHttpT manager (testPrometheusMetrics brig),
@@ -79,7 +76,7 @@ testMetricsEndpoint brig = do
       rsp <- responseBody <$> get (brig . path "i/metrics")
       -- is there some responseBodyAsText function used elsewhere?
       let asText = fromMaybe "" (fromByteString' (fromMaybe "" rsp))
-      return $ fromRight 0 (parseOnly (parseCount endpoint m) asText)
+      pure $ fromRight 0 (parseOnly (parseCount endpoint m) asText)
     parseCount :: Text -> Text -> Parser Integer
     parseCount endpoint m =
       manyTill anyChar (string ("http_request_duration_seconds_count{handler=\"" <> endpoint <> "\",method=\"" <> m <> "\",status_code=\"200\"} "))
diff --git a/services/brig/test/integration/API/Provider.hs b/services/brig/test/integration/API/Provider.hs
index 0c5904bf2c..7cd730553b 100644
--- a/services/brig/test/integration/API/Provider.hs
+++ b/services/brig/test/integration/API/Provider.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE NondecreasingIndentation #-}
-{-# LANGUAGE RecordWildCards #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
 
 -- This file is part of the Wire Server implementation.
@@ -93,7 +92,7 @@ import qualified Wire.API.Team.Feature as Public
 
 tests :: Domain -> Config -> Manager -> DB.ClientState -> Brig -> Cannon -> Galley -> IO TestTree
 tests dom conf p db b c g = do
-  return $
+  pure $
     testGroup
       "provider"
       [ testGroup
@@ -457,14 +456,14 @@ testListServices config db brig = do
             ("search for " <> show name <> " without and with tags")
             (serviceProfilePageResults r1)
             (serviceProfilePageResults r2)
-        return r1
+        pure r1
   -- This function searches for a prefix and check that the results match
   -- our known list of services
   let searchAndCheck :: HasCallStack => Name -> Http [ServiceProfile]
       searchAndCheck name = do
         result <- search name
         assertServiceDetails ("name " <> show name) (select name services) result
-        return (serviceProfilePageResults result)
+        pure (serviceProfilePageResults result)
   -- Search for our unique prefix and check that all services are found
   search (Name uniq) >>= assertServiceDetails ("all with prefix " <> show uniq) services
   -- Search by exact name and check that only one service is found
@@ -594,7 +593,7 @@ testMessageBot config db brig galley cannon = withTestService config db brig def
   usr <- createUser "User" brig
   let uid = userId usr
   let quid = userQualifiedId usr
-  let new = defNewClient PermanentClientType [somePrekeys !! 0] (someLastPrekeys !! 0)
+  let new = defNewClient PermanentClientType [head somePrekeys] (head someLastPrekeys)
   _rs <- addClient brig uid new <!! const 201 === statusCode
   let Just uc = clientId <$> responseJsonMaybe _rs
   -- Create conversation
@@ -616,7 +615,7 @@ testBadFingerprint config db brig galley _cannon = do
     -- Prepare user with client
     usr <- createUser "User" brig
     let uid = userId usr
-    let new = defNewClient PermanentClientType [somePrekeys !! 0] (someLastPrekeys !! 0)
+    let new = defNewClient PermanentClientType [head somePrekeys] (head someLastPrekeys)
     _rs <- addClient brig uid new <!! const 201 === statusCode
     -- Create conversation
     _rs <- createConv galley uid [] <!! const 201 === statusCode
@@ -673,7 +672,7 @@ testMessageBotTeam config db brig galley cannon = withTestService config db brig
   let sid = sref ^. serviceRefId
   -- Prepare user with client
   (uid, tid) <- Team.createUserWithTeam brig
-  let new = defNewClient PermanentClientType [somePrekeys !! 0] (someLastPrekeys !! 0)
+  let new = defNewClient PermanentClientType [head somePrekeys] (head someLastPrekeys)
   _rs <- addClient brig uid new <!! const 201 === statusCode
   let Just uc = clientId <$> responseJsonMaybe _rs
   -- Whitelist the bot
@@ -804,7 +803,7 @@ testSearchWhitelist config db brig galley = do
             ("search for " <> show mbName <> " with and without filtering")
             r1
             r2
-        return r1
+        pure r1
   -- Check that search finds all services that we created
   search (Just uniq)
     >>= assertServiceDetails ("all with prefix " <> show uniq) services
@@ -826,7 +825,7 @@ testSearchWhitelist config db brig galley = do
       searchAndCheck (Name name) = do
         result <- search (Just name)
         assertServiceDetails ("name " <> show name) (select name services) result
-        return (serviceProfilePageResults result)
+        pure (serviceProfilePageResults result)
   -- Search by exact name and check that only one service is found
   forM_ (take 3 services) $ \(sid, Name name) ->
     search (Just name) >>= assertServiceDetails ("name " <> show name) [(sid, Name name)]
@@ -1491,7 +1490,7 @@ randomProvider db brig = do
   -- Fetch
   _rs <- getProvider brig pid <!! const 200 === statusCode
   let Just prv = responseJsonMaybe _rs
-  return prv
+  pure prv
 
 addGetService :: HasCallStack => Brig -> ProviderId -> NewService -> Http Service
 addGetService brig pid new = do
@@ -1500,7 +1499,7 @@ addGetService brig pid new = do
   let sid = rsNewServiceId srs
   _rs <- getService brig pid sid <!! const 200 === statusCode
   let Just svc = responseJsonMaybe _rs
-  return svc
+  pure svc
 
 enableService :: HasCallStack => Brig -> ProviderId -> ServiceId -> Http ()
 enableService brig pid sid = do
@@ -1555,7 +1554,7 @@ dewhitelistService brig uid tid pid sid =
 defNewService :: MonadIO m => Config -> m NewService
 defNewService config = liftIO $ do
   key <- readServiceKey (publicKey config)
-  return
+  pure
     NewService
       { newServiceName = defServiceName,
         newServiceSummary = unsafeRange defProviderSummary,
@@ -1617,19 +1616,19 @@ readServiceKey :: MonadIO m => FilePath -> m ServiceKeyPEM
 readServiceKey fp = liftIO $ do
   bs <- BS.readFile fp
   let Right [k] = pemParseBS bs
-  return (ServiceKeyPEM k)
+  pure (ServiceKeyPEM k)
 
 randServiceKey :: MonadIO m => m ServiceKeyPEM
 randServiceKey = liftIO $ do
   kp <- generateRSAKey' 4096 65537
   Right [k] <- pemParseBS . C8.pack <$> writePublicKey kp
-  return (ServiceKeyPEM k)
+  pure (ServiceKeyPEM k)
 
 waitFor :: MonadIO m => Timeout -> (a -> Bool) -> m a -> m a
 waitFor t f ma = do
   a <- ma
   if
-      | f a -> return a
+      | f a -> pure a
       | t <= 0 -> liftIO $ throwM TimedOut
       | otherwise -> do
         liftIO $ threadDelay (1 # Second)
@@ -1659,7 +1658,7 @@ registerService config db brig = do
   let pid = providerId prv
   let sid = serviceId svc
   enableService brig pid sid
-  return (newServiceRef sid pid)
+  pure (newServiceRef sid pid)
 
 runService ::
   Config ->
@@ -1706,8 +1705,8 @@ defServiceApp buf =
       case eitherDecode js of
         Left e -> k $ responseLBS status400 [] (LC8.pack e)
         Right new -> do
-          let pks = [somePrekeys !! 0]
-          let lpk = someLastPrekeys !! 0
+          let pks = [head somePrekeys]
+          let lpk = head someLastPrekeys
           let rsp =
                 Ext.NewBotResponse
                   { Ext.rsNewBotPrekeys = pks,
@@ -1842,7 +1841,7 @@ svcAssertBotCreated buf bid cid = liftIO $ do
       assertEqual "conv" cid (testBotConv b ^. Ext.botConvId)
       -- TODO: Verify the conversation name
       -- TODO: Verify the list of members
-      return b
+      pure b
     _ -> throwM $ HUnitFailure Nothing "Event timeout (TestBotCreated)"
 
 svcAssertMessage :: MonadIO m => Chan TestBotEvent -> Qualified UserId -> OtrMessage -> Qualified ConvId -> m ()
@@ -1949,7 +1948,7 @@ testAddRemoveBotUtil localDomain pid sid cid u1 u2 h sref buf brig galley cannon
     forM_ [ws1, ws2] $ \ws -> wsAssertMemberJoin ws qcid quid1 [qbuid]
     -- Member join event for the bot
     svcAssertMemberJoin buf quid1 [qbuid] qcid
-    return (rs, bot)
+    pure (rs, bot)
   let bid = rsAddBotId rs
       buid = botUserId bid
       -- Check that the bot token grants access to the right user and conversation
@@ -2033,11 +2032,11 @@ testMessageBotUtil quid uc cid pid sid sref buf brig galley cannon = do
     assertEqual "service" (Just sref) (omService =<< other)
   -- The bot greets the user
   WS.bracketR cannon uid $ \ws -> do
-    postBotMessage galley bid bc cid [(uid, uc, (toBase64Text "Hi User!"))]
+    postBotMessage galley bid bc cid [(uid, uc, toBase64Text "Hi User!")]
       !!! const 201 === statusCode
     wsAssertMessage ws qcid (qUntagged lbuid) bc uc (toBase64Text "Hi User!")
   -- The user replies
-  postMessage galley uid uc cid [(buid, bc, (toBase64Text "Hi Bot"))]
+  postMessage galley uid uc cid [(buid, bc, toBase64Text "Hi Bot")]
     !!! const 201 === statusCode
   let msg = OtrMessage uc bc (toBase64Text "Hi Bot") (Just "data")
   svcAssertMessage buf quid msg qcid
@@ -2070,7 +2069,7 @@ prepareBotUsersTeam brig galley sref = do
   whitelistService brig uid1 tid pid sid
   -- Create conversation
   cid <- Team.createTeamConv galley tid uid1 [uid2] Nothing
-  return (u1, u2, h, tid, cid, pid, sid)
+  pure (u1, u2, h, tid, cid, pid, sid)
 
 addBotConv ::
   HasCallStack =>
@@ -2101,7 +2100,7 @@ addBotConv localDomain brig cannon uid1 uid2 cid pid sid buf = do
     forM_ [ws1, ws2] $ \ws -> wsAssertMemberJoin ws qcid quid1 [qbotId]
     -- Member join event for the bot
     svcAssertMemberJoin buf quid1 [qbotId] qcid
-    return (rsAddBotId rs)
+    pure (rsAddBotId rs)
 
 ----------------------------------------------------------------------------
 -- Service search utilities (abstracted out because we have more than one
diff --git a/services/brig/test/integration/API/Settings.hs b/services/brig/test/integration/API/Settings.hs
index 639961890e..5f062f1bbe 100644
--- a/services/brig/test/integration/API/Settings.hs
+++ b/services/brig/test/integration/API/Settings.hs
@@ -38,7 +38,7 @@ import Test.Tasty.HUnit
 import Util
 
 tests :: Opts -> Manager -> Brig -> Galley -> IO TestTree
-tests defOpts manager brig galley = return $ do
+tests defOpts manager brig galley = pure $ do
   testGroup
     "settings"
     [ testGroup
diff --git a/services/brig/test/integration/API/Team.hs b/services/brig/test/integration/API/Team.hs
index 5f59e08115..dfc02eeb6d 100644
--- a/services/brig/test/integration/API/Team.hs
+++ b/services/brig/test/integration/API/Team.hs
@@ -66,7 +66,7 @@ tests :: Opt.Opts -> Manager -> Nginz -> Brig -> Cannon -> Galley -> AWS.Env ->
 tests conf m n b c g aws = do
   let tl = TeamSizeLimit . Opt.setMaxTeamSize . Opt.optSettings $ conf
   let it = Opt.setTeamInvitationTimeout . Opt.optSettings $ conf
-  return $
+  pure $
     testGroup
       "team"
       [ testGroup "invitation" $
@@ -303,7 +303,7 @@ testInvitationEmailAndPhoneAccepted brig galley = do
   (profile, invitation) <- createAndVerifyInvitation (extAccept inviteeEmail inviteeName inviteePhone phoneCode) extInvite brig galley
   liftIO $ assertEqual "Wrong name in profile" (Just inviteeName) (userDisplayName . selfUser <$> profile)
   liftIO $ assertEqual "Wrong name in invitation" (Just inviteeName) (inInviteeName invitation)
-  liftIO $ assertEqual "Wrong phone number in profile" (Just inviteePhone) (join (userPhone . selfUser <$> profile))
+  liftIO $ assertEqual "Wrong phone number in profile" (Just inviteePhone) ((userPhone . selfUser) =<< profile)
   liftIO $ assertEqual "Wrong phone number in invitation" (Just inviteePhone) (inInviteePhone invitation)
 
 -- | FUTUREWORK: this is an alternative helper to 'createPopulatedBindingTeam'.  it has been
@@ -314,7 +314,7 @@ createAndVerifyInvitation ::
   InvitationRequest ->
   Brig ->
   Galley ->
-  Http ((Maybe SelfProfile), Invitation)
+  Http (Maybe SelfProfile, Invitation)
 createAndVerifyInvitation acceptFn invite brig galley = do
   createAndVerifyInvitation' Nothing acceptFn invite brig galley
 
@@ -335,7 +335,7 @@ createAndVerifyInvitation' ::
   InvitationRequest ->
   Brig ->
   Galley ->
-  m ((Maybe SelfProfile), Invitation)
+  m (Maybe SelfProfile, Invitation)
 createAndVerifyInvitation' replacementBrigApp acceptFn invite brig galley = do
   (inviter, tid) <- createUserWithTeam brig
   let invitationHandshake ::
@@ -375,7 +375,7 @@ createAndVerifyInvitation' replacementBrigApp acceptFn invite brig galley = do
   liftIO $ assertEqual "Member has no/wrong invitation metadata" invmeta (mem ^. Team.invitation)
   conns <- listConnections invitee brig
   liftIO $ assertBool "User should have no connections" (null (clConnections conns) && not (clHasMore conns))
-  return (responseJsonMaybe rsp2, invitation)
+  pure (responseJsonMaybe rsp2, invitation)
 
 testCreateTeam :: Brig -> Galley -> AWS.Env -> Http ()
 testCreateTeam brig galley aws = do
@@ -592,7 +592,7 @@ testInvitationPaging brig = do
         liftIO $ assertEqual "page size" actualPageLen (length invs)
         liftIO $ assertEqual "has more" (count' < total) more
         liftIO $ validateInv `mapM_` invs
-        return (count', fmap inInvitation . listToMaybe . reverse $ invs)
+        pure (count', fmap inInvitation . listToMaybe . reverse $ invs)
       validateInv :: Invitation -> Assertion
       validateInv inv = do
         assertEqual "tid" tid (inTeam inv)
diff --git a/services/brig/test/integration/API/Team/Util.hs b/services/brig/test/integration/API/Team/Util.hs
index 9257bc2678..59e62af52b 100644
--- a/services/brig/test/integration/API/Team/Util.hs
+++ b/services/brig/test/integration/API/Team/Util.hs
@@ -62,11 +62,11 @@ createPopulatedBindingTeamWithNamesAndHandles ::
   Int ->
   m (TeamId, User, [User])
 createPopulatedBindingTeamWithNamesAndHandles brig numMembers = do
-  names <- forM [1 .. numMembers] $ \_ -> randomName
+  names <- forM [1 .. numMembers] $ const randomName
   (tid, owner, mems) <- createPopulatedBindingTeamWithNames brig names
   membersWithHandle <- mapM (setRandomHandle brig) mems
   ownerWithHandle <- setRandomHandle brig owner
-  return (tid, ownerWithHandle, membersWithHandle)
+  pure (tid, ownerWithHandle, membersWithHandle)
 
 createPopulatedBindingTeam ::
   (MonadIO m, MonadCatch m, MonadFail m, MonadHttp m, HasCallStack) =>
@@ -74,9 +74,9 @@ createPopulatedBindingTeam ::
   Int ->
   m (TeamId, UserId, [User])
 createPopulatedBindingTeam brig numMembers = do
-  names <- forM [1 .. numMembers] $ \_ -> randomName
+  names <- forM [1 .. numMembers] $ const randomName
   (tid, owner, others) <- createPopulatedBindingTeamWithNames brig names
-  return (tid, userId owner, others)
+  pure (tid, userId owner, others)
 
 createPopulatedBindingTeamWithNames ::
   (MonadIO m, MonadCatch m, MonadFail m, MonadHttp m, HasCallStack) =>
@@ -118,7 +118,7 @@ createTeam u galley = do
           . expect2xx
           . lbytes (encode newTeam)
       )
-  maybe (error "invalid team id") return $
+  maybe (error "invalid team id") pure $
     fromByteString $
       getHeader' "Location" r
 
@@ -128,7 +128,7 @@ createTeam u galley = do
 createUserWithTeam :: (MonadIO m, MonadHttp m, MonadCatch m, MonadThrow m) => Brig -> m (UserId, TeamId)
 createUserWithTeam brig = do
   (user, tid) <- createUserWithTeam' brig
-  return (userId user, tid)
+  pure (userId user, tid)
 
 -- | Create user and binding team.
 --
@@ -149,7 +149,7 @@ createUserWithTeam' brig = do
   let Just tid = userTeam user
   selfTeam <- userTeam . selfUser <$> getSelfProfile brig (userId user)
   liftIO $ assertBool "Team ID in self profile and team table do not match" (selfTeam == Just tid)
-  return (user, tid)
+  pure (user, tid)
 
 -- | Create a team member with given permissions.
 createTeamMember ::
@@ -165,7 +165,7 @@ createTeamMember ::
 createTeamMember brig galley owner tid perm = do
   user <- inviteAndRegisterUser owner tid brig
   updatePermissions owner tid (userId user, perm) galley
-  return user
+  pure user
 
 inviteAndRegisterUser ::
   (MonadIO m, MonadCatch m, MonadFail m, MonadHttp m, HasCallStack) =>
@@ -192,7 +192,7 @@ inviteAndRegisterUser u tid brig = do
   liftIO $ assertEqual "Team ID in registration and team table do not match" (Just tid) (userTeam invitee)
   selfTeam <- userTeam . selfUser <$> getSelfProfile brig (userId invitee)
   liftIO $ assertEqual "Team ID in self profile and team table do not match" selfTeam (Just tid)
-  return invitee
+  pure invitee
 
 updatePermissions :: HasCallStack => UserId -> TeamId -> (UserId, Team.Permissions) -> Galley -> Http ()
 updatePermissions from tid (to, perm) galley =
@@ -224,7 +224,7 @@ createTeamConv g tid u us mtimer = do
       )
       <!! const 201
       === statusCode
-  maybe (error "invalid conv id") return $
+  maybe (error "invalid conv id") pure $
     fromByteString $
       getHeader' "Location" r
 
@@ -285,7 +285,7 @@ putLHWhitelistTeam galley tid = do
     )
 
 accept :: Email -> InvitationCode -> RequestBody
-accept email code = acceptWithName (Name "Bob") email code
+accept = acceptWithName (Name "Bob")
 
 acceptWithName :: Name -> Email -> InvitationCode -> RequestBody
 acceptWithName name email code =
@@ -357,7 +357,7 @@ getInvitation brig c = do
       brig
         . path "/teams/invitations/info"
         . queryItem "code" (toByteString' c)
-  return . decode . fromMaybe "" $ responseBody r
+  pure . decode . fromMaybe "" $ responseBody r
 
 postInvitation ::
   (MonadIO m, MonadHttp m, HasCallStack) =>
@@ -407,7 +407,7 @@ getInvitationCode brig t ref = do
           . queryItem "invitation_id" (toByteString' ref)
       )
   let lbs = fromMaybe "" $ responseBody r
-  return $ fromByteString . fromMaybe (error "No code?") $ T.encodeUtf8 <$> (lbs ^? key "code" . _String)
+  pure $ fromByteString (maybe (error "No code?") T.encodeUtf8 (lbs ^? key "code" . _String))
 
 assertNoInvitationCode :: HasCallStack => Brig -> TeamId -> InvitationId -> (MonadIO m, MonadHttp m, MonadCatch m) => m ()
 assertNoInvitationCode brig t i =
diff --git a/services/brig/test/integration/API/TeamUserSearch.hs b/services/brig/test/integration/API/TeamUserSearch.hs
index dc7f59af06..7fbf184cb7 100644
--- a/services/brig/test/integration/API/TeamUserSearch.hs
+++ b/services/brig/test/integration/API/TeamUserSearch.hs
@@ -46,7 +46,7 @@ type TestConstraints m = (MonadFail m, MonadCatch m, MonadIO m, MonadHttp m)
 
 tests :: Opt.Opts -> Manager -> Galley -> Brig -> IO TestTree
 tests opts mgr _galley brig = do
-  return $
+  pure $
     testGroup "/teams/:tid/search" $
       [ testWithNewIndex "can find user by email" (testSearchByEmailSameTeam brig),
         testWithNewIndex "empty query returns the whole team sorted" (testEmptyQuerySorted brig),
diff --git a/services/brig/test/integration/API/User.hs b/services/brig/test/integration/API/User.hs
index de4e9bcdd1..f2c41833e2 100644
--- a/services/brig/test/integration/API/User.hs
+++ b/services/brig/test/integration/API/User.hs
@@ -59,7 +59,7 @@ tests conf fbc fgc p b c ch g n aws db = do
   let cl = ConnectionLimit $ Opt.setUserMaxConnections (Opt.optSettings conf)
   let at = Opt.setActivationTimeout (Opt.optSettings conf)
   z <- mkZAuthEnv (Just conf)
-  return $
+  pure $
     testGroup
       "user"
       [ API.User.Client.tests cl at conf p db b c g,
diff --git a/services/brig/test/integration/API/User/Account.hs b/services/brig/test/integration/API/User/Account.hs
index b45ebf2db2..86883e9615 100644
--- a/services/brig/test/integration/API/User/Account.hs
+++ b/services/brig/test/integration/API/User/Account.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE NumericUnderscores #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
 
 -- This file is part of the Wire Server implementation.
@@ -68,6 +67,7 @@ import qualified Data.Vector as Vec
 import Federator.MockServer (FederatedRequest (..), MockException (..))
 import Galley.Types.Teams (noPermissions)
 import Imports hiding (head)
+import qualified Imports
 import qualified Network.HTTP.Types as HTTP
 import qualified Network.HTTP.Types as Http
 import qualified Network.Wai as Wai
@@ -393,7 +393,7 @@ testCreateUserPending _ brig = do
     const 200 === statusCode
     const (Just True) === \rs' -> do
       self <- responseJsonMaybe rs'
-      return $! isNothing (userIdentity (selfUser self))
+      pure $! isNothing (userIdentity (selfUser self))
   -- should not appear in search
   suid <- userId <$> randomUser brig
   Search.refreshIndex brig
@@ -767,12 +767,12 @@ testCreateUserAnonExpiry b = do
   alice <- randomUser b
   now <- liftIO getCurrentTime
   bob <- createAnonUserExpiry (Just 2) "bob" b
-  liftIO $ assertBool "expiry not set on regular creation" (not $ isJust $ userExpire alice)
+  liftIO $ assertBool "expiry not set on regular creation" (isNothing (userExpire alice))
   ensureExpiry now (fromUTCTimeMillis <$> userExpire bob) "bob/register"
   resAlice <- getProfile (userId u1) (userId alice)
   resBob <- getProfile (userId u1) (userId bob)
   selfBob <- get (b . zUser (userId bob) . path "self") <!! const 200 === statusCode
-  liftIO $ assertBool "Bob must not be in a deleted state initially" (fromMaybe True (not <$> deleted selfBob))
+  liftIO $ assertBool "Bob must not be in a deleted state initially" (maybe True not (deleted selfBob))
   liftIO $ assertBool "Regular user should not have any expiry" (null $ expire resAlice)
   ensureExpiry now (expire resBob) "bob/public"
   ensureExpiry now (expire selfBob) "bob/self"
@@ -786,7 +786,7 @@ testCreateUserAnonExpiry b = do
     awaitExpiry n zusr uid = do
       -- after expiration, a profile lookup should trigger garbage collection of ephemeral users
       r <- getProfile zusr uid
-      when (statusCode r == 200 && deleted r == Nothing && n > 0) $ do
+      when (statusCode r == 200 && isNothing (deleted r) && n > 0) $ do
         liftIO $ threadDelay 1000000
         awaitExpiry (n -1) zusr uid
     ensureExpiry :: UTCTime -> Maybe UTCTime -> String -> Http ()
@@ -799,9 +799,9 @@ testCreateUserAnonExpiry b = do
         liftIO $ assertBool "expiry must in be the future" (diff >= fromIntegral minExp)
         liftIO $ assertBool "expiry must be less than 10 days" (diff < fromIntegral maxExp)
     expire :: ResponseLBS -> Maybe UTCTime
-    expire r = join $ field "expires_at" <$> responseJsonMaybe r
+    expire r = field "expires_at" =<< responseJsonMaybe r
     deleted :: ResponseLBS -> Maybe Bool
-    deleted r = join $ field "deleted" <$> responseJsonMaybe r
+    deleted r = field "deleted" =<< responseJsonMaybe r
     field :: FromJSON a => Text -> Value -> Maybe a
     field f u = u ^? key f >>= maybeFromJSON
 
@@ -1030,7 +1030,7 @@ testGetByIdentity brig = do
     const 200 === statusCode
     const (Just [uid]) === getUids
   where
-    getUids r = return . fmap (userId . accountUser) =<< responseJsonMaybe r
+    getUids r = fmap (userId . accountUser) <$> responseJsonMaybe r
 
 testPasswordSet :: Brig -> Http ()
 testPasswordSet brig = do
@@ -1254,7 +1254,7 @@ testDeleteUserByPassword brig cannon aws = do
   con32 <- putConnection brig uid3 uid2 Accepted <!! const 200 === statusCode
   con23 <- getConnection brig uid2 uid3 <!! const 200 === statusCode
   -- Register a client
-  addClient brig uid1 (defNewClient PermanentClientType [somePrekeys !! 0] (someLastPrekeys !! 0))
+  addClient brig uid1 (defNewClient PermanentClientType [Imports.head somePrekeys] (Imports.head someLastPrekeys))
     !!! const 201 === statusCode
   -- Initial login
   login brig (defEmailLogin email) PersistentCookie
@@ -1290,7 +1290,7 @@ testDeleteUserWithLegalHold brig cannon aws = do
   user <- randomUser brig
   let uid = userId user
   -- Register a legalhold client
-  addClientInternal brig uid (defNewClient LegalHoldClientType [somePrekeys !! 0] (someLastPrekeys !! 0))
+  addClientInternal brig uid (defNewClient LegalHoldClientType [Imports.head somePrekeys] (Imports.head someLastPrekeys))
     !!! const 201 === statusCode
   liftIO $ Util.assertUserJournalQueue "user activate testDeleteInternal1: " aws (userActivateJournaled user)
   setHandleAndDeleteUser brig cannon user [] aws $
@@ -1474,7 +1474,7 @@ testUpdateSSOId brig galley = do
         member <- createTeamMember brig galley owner teamid noPermissions
         when hasPhone $ do
           updatePhone brig (userId member) =<< randomPhone
-        when (not hasEmail) $ do
+        unless hasEmail $ do
           error "not implemented"
         selfUser <$> (responseJsonError =<< get (brig . path "/self" . zUser (userId member)))
   let ssoids1 = [UserSSOId (mkSampleUref "1" "1"), UserSSOId (mkSampleUref "1" "2")]
@@ -1487,8 +1487,8 @@ testUpdateSSOId brig galley = do
         -- , mkMember False  False
         -- , mkMember False  True
       ]
-  sequence_ $ zipWith go users ssoids1
-  sequence_ $ zipWith go users ssoids2
+  zipWithM_ go users ssoids1
+  zipWithM_ go users ssoids2
 
 testDomainsBlockedForRegistration :: Opt.Opts -> Brig -> Http ()
 testDomainsBlockedForRegistration opts brig = withDomainsBlockedForRegistration opts ["bad1.domain.com", "bad2.domain.com"] $ do
diff --git a/services/brig/test/integration/API/User/Auth.hs b/services/brig/test/integration/API/User/Auth.hs
index 215832218e..b13b261d5a 100644
--- a/services/brig/test/integration/API/User/Auth.hs
+++ b/services/brig/test/integration/API/User/Auth.hs
@@ -171,7 +171,7 @@ randomAccessToken :: forall u a. ZAuth.TokenPair u a => ZAuth (ZAuth.Token a)
 randomAccessToken = randomUserToken @u >>= ZAuth.newAccessToken
 
 randomUserToken :: ZAuth.UserTokenLike u => ZAuth (ZAuth.Token u)
-randomUserToken = (Id <$> liftIO UUID.nextRandom) >>= ZAuth.newUserToken
+randomUserToken = liftIO UUID.nextRandom >>= ZAuth.newUserToken . Id
 
 -------------------------------------------------------------------------------
 -- Nginz authentication tests (end-to-end sanity checks)
@@ -192,14 +192,14 @@ testNginz b n = do
   -- Note: If you get 403 test failures:
   -- 1. check that the private/public keys in brig and nginz match.
   -- 2. check that the nginz acl file is correct.
-  _rs <- get (n . path "/clients" . header "Authorization" ("Bearer " <> (toByteString' t)))
+  _rs <- get (n . path "/clients" . header "Authorization" ("Bearer " <> toByteString' t))
   liftIO $ assertEqual "Ensure nginz is started. Ensure nginz and brig share the same private/public zauth keys. Ensure ACL file is correct." 200 (statusCode _rs)
   -- ensure nginz allows refresh at /access
   _rs <-
-    post (n . path "/access" . cookie c . header "Authorization" ("Bearer " <> (toByteString' t))) <!! do
+    post (n . path "/access" . cookie c . header "Authorization" ("Bearer " <> toByteString' t)) <!! do
       const 200 === statusCode
   -- ensure regular user tokens can fetch notifications
-  get (n . path "/notifications" . header "Authorization" ("Bearer " <> (toByteString' t))) !!! const 200 === statusCode
+  get (n . path "/notifications" . header "Authorization" ("Bearer " <> toByteString' t)) !!! const 200 === statusCode
 
 testNginzLegalHold :: Brig -> Galley -> Nginz -> Http ()
 testNginzLegalHold b g n = do
@@ -226,13 +226,13 @@ testNginzLegalHold b g n = do
     pure (c, t)
 
   -- ensure nginz allows passing legalhold cookies / tokens through to /access
-  post (n . path "/access" . cookie c . header "Authorization" ("Bearer " <> (toByteString' t))) !!! do
+  post (n . path "/access" . cookie c . header "Authorization" ("Bearer " <> toByteString' t)) !!! do
     const 200 === statusCode
   -- ensure legalhold tokens CANNOT fetch /clients
-  get (n . path "/clients" . header "Authorization" ("Bearer " <> (toByteString' t))) !!! const 403 === statusCode
-  get (n . path "/self" . header "Authorization" ("Bearer " <> (toByteString' t))) !!! const 403 === statusCode
+  get (n . path "/clients" . header "Authorization" ("Bearer " <> toByteString' t)) !!! const 403 === statusCode
+  get (n . path "/self" . header "Authorization" ("Bearer " <> toByteString' t)) !!! const 403 === statusCode
   -- ensure legal hold tokens can fetch notifications
-  get (n . path "/notifications" . header "Authorization" ("Bearer " <> (toByteString' t))) !!! const 200 === statusCode
+  get (n . path "/notifications" . header "Authorization" ("Bearer " <> toByteString' t)) !!! const 200 === statusCode
 
 -- | Corner case for 'testNginz': when upgrading a wire backend from the old behavior (setting
 -- cookie domain to eg. @*.wire.com@) to the new behavior (leaving cookie domain empty,
@@ -901,7 +901,7 @@ getAndTestDBSupersededCookieAndItsValidSuccessor config b n = do
     [Nothing] @=? map cookieSucc _cs
   -- Return non-expired cookie but removed from DB (because it was renewed)
   -- and a valid cookie
-  return (c, c')
+  pure (c, c')
 
 testNewSessionCookie :: Opts.Opts -> Brig -> Http ()
 testNewSessionCookie config b = do
@@ -1073,7 +1073,7 @@ testTooManyCookies config b = do
     loginWhenAllowed pwl t = do
       x <- login b pwl t <* wait
       case statusCode x of
-        200 -> return $ decodeCookie x
+        200 -> pure $ decodeCookie x
         429 -> do
           -- After the amount of time specified in "Retry-After", though,
           -- throttling should stop and login should work again
@@ -1126,12 +1126,12 @@ testReauthentication b = do
 -----------------------------------------------------------------------------
 -- Helpers
 
-prepareLegalHoldUser :: Brig -> Galley -> Http (UserId)
+prepareLegalHoldUser :: Brig -> Galley -> Http UserId
 prepareLegalHoldUser brig galley = do
   (uid, tid) <- createUserWithTeam brig
   -- enable it for this team - without that, legalhold login will fail.
   putLHWhitelistTeam galley tid !!! const 200 === statusCode
-  return uid
+  pure uid
 
 getCookieId :: forall u. (HasCallStack, ZAuth.UserTokenLike u) => Http.Cookie -> CookieId
 getCookieId c =
@@ -1153,7 +1153,7 @@ listCookiesWithLabel b u l = do
       )
       <!! const 200 === statusCode
   let Just cs = cookieList <$> responseJsonMaybe rs
-  return cs
+  pure cs
   where
     labels = BS.intercalate "," $ map toByteString' l
 
diff --git a/services/brig/test/integration/API/User/Connection.hs b/services/brig/test/integration/API/User/Connection.hs
index 0b73129ce8..555f9e576f 100644
--- a/services/brig/test/integration/API/User/Connection.hs
+++ b/services/brig/test/integration/API/User/Connection.hs
@@ -624,7 +624,7 @@ testLocalConnectionsPaging b = do
       let (conns, more) = (fmap clConnections &&& fmap clHasMore) $ responseJsonMaybe r
       liftIO $ assertEqual "page size" (Just n) (length <$> conns)
       liftIO $ assertEqual "has more" (Just (count' < total)) more
-      return . (count',) $ (conns >>= fmap (qUnqualified . ucTo) . listToMaybe . reverse)
+      pure . (count',) $ (conns >>= fmap (qUnqualified . ucTo) . listToMaybe . reverse)
 
 testAllConnectionsPaging :: Brig -> DB.ClientState -> Http ()
 testAllConnectionsPaging b db = do
@@ -688,7 +688,7 @@ testConnectionLimit brig (ConnectionLimit l) = do
     newConn from = do
       to <- userId <$> randomUser brig
       postConnection brig from to !!! const 201 === statusCode
-      return to
+      pure to
     assertLimited = do
       const 403 === statusCode
       const (Just "connection-limit") === fmap Error.label . responseJsonMaybe
@@ -713,7 +713,7 @@ testConnectionLimitQualified brig (ConnectionLimit l) = do
     newConn from = do
       to <- userQualifiedId <$> randomUser brig
       postConnectionQualified brig from to !!! const 201 === statusCode
-      return to
+      pure to
     assertLimited = do
       const 403 === statusCode
       const (Just "connection-limit") === fmap Error.label . responseJsonMaybe
diff --git a/services/brig/test/integration/API/User/RichInfo.hs b/services/brig/test/integration/API/User/RichInfo.hs
index 1597867584..66c8b9b247 100644
--- a/services/brig/test/integration/API/User/RichInfo.hs
+++ b/services/brig/test/integration/API/User/RichInfo.hs
@@ -124,7 +124,7 @@ testRichInfoSizeLimit brig conf = do
           ]
       bad2 =
         mkRichInfoAssocList $
-          [0 .. ((maxSize `div` 2))]
+          [0 .. (maxSize `div` 2)]
             <&> \i -> RichField (CI.mk $ Text.pack $ show i) "#"
   putRichInfo brig owner bad1 !!! const 413 === statusCode
   putRichInfo brig owner bad2 !!! const 413 === statusCode
diff --git a/services/brig/test/integration/API/User/Util.hs b/services/brig/test/integration/API/User/Util.hs
index c13591cbf4..916c527260 100644
--- a/services/brig/test/integration/API/User/Util.hs
+++ b/services/brig/test/integration/API/User/Util.hs
@@ -105,7 +105,7 @@ setRandomHandle brig user = do
     )
     !!! const 200
     === statusCode
-  return user {userHandle = Just (Handle h)}
+  pure user {userHandle = Just (Handle h)}
 
 -- Note: This actually _will_ send out an email, so we ensure that the email
 --       used here has a domain 'simulator.amazonses.com'.
@@ -139,7 +139,7 @@ createRandomPhoneUser brig = do
   get (brig . path "/self" . zUser uid) !!! do
     const 200 === statusCode
     const (Just phn) === (userPhone <=< responseJsonMaybe)
-  return (uid, phn)
+  pure (uid, phn)
 
 initiatePasswordReset :: Brig -> Email -> (MonadIO m, MonadHttp m) => m ResponseLBS
 initiatePasswordReset brig email =
@@ -205,7 +205,7 @@ preparePasswordReset brig cs email uid newpw = do
   let Just pwcode = PasswordResetCode . Ascii.unsafeFromText <$> (lbs ^? key "code" . _String)
   ident <- PasswordResetIdentityKey <$> runSem (mkPasswordResetKey uid)
   let complete = CompletePasswordReset ident pwcode newpw
-  return complete
+  pure complete
   where
     runSem = liftIO . runFinal @IO . interpretClientToIO cs . codeStoreToCassandra @DB.Client
 
@@ -331,7 +331,7 @@ countCookies brig u label = do
       )
       <!! const 200
       === statusCode
-  return $ Vec.length <$> (preview (key "cookies" . _Array) =<< responseJsonMaybe @Value r)
+  pure $ Vec.length <$> (preview (key "cookies" . _Array) =<< responseJsonMaybe @Value r)
 
 assertConnections :: (MonadCatch m, MonadIO m, MonadHttp m, HasCallStack) => Brig -> UserId -> [ConnectionStatus] -> m ()
 assertConnections brig u connections =
diff --git a/services/brig/test/integration/API/UserPendingActivation.hs b/services/brig/test/integration/API/UserPendingActivation.hs
index 4e3e02b60b..b42b51868a 100644
--- a/services/brig/test/integration/API/UserPendingActivation.hs
+++ b/services/brig/test/integration/API/UserPendingActivation.hs
@@ -70,7 +70,7 @@ import Wire.API.User.Scim (CreateScimToken (..), ScimToken, ScimUserExtra (ScimU
 
 tests :: Opts -> Manager -> ClientState -> Brig -> Galley -> Spar -> IO TestTree
 tests opts m db brig galley spar = do
-  return $
+  pure $
     testGroup
       "cleanExpiredPendingInvitations"
       [ test m "expired users get cleaned" (testCleanExpiredPendingInvitations opts db brig galley spar),
@@ -139,7 +139,7 @@ userExists uid = do
     case x of
       Nothing -> False
       Just (_, mbStatus) ->
-        maybe True (/= Deleted) mbStatus
+        Just Deleted /= mbStatus
   where
     usersSelect :: PrepQuery R (Identity UserId) (UserId, Maybe AccountStatus)
     usersSelect = "SELECT id, status FROM user where id = ?"
@@ -176,7 +176,7 @@ createUserWithTeamDisableSSO brg gly = do
   () <-
     Control.Exception.assert {- "Team ID in self profile and team table do not match" -} (selfTeam == Just tid) $
       pure ()
-  return (uid, tid)
+  pure (uid, tid)
 
 randomScimUser :: (HasCallStack, MonadRandom m, MonadIO m) => m (Scim.User.User SparTag)
 randomScimUser = fst <$> randomScimUserWithSubject
@@ -310,7 +310,7 @@ getInvitationCode brig t ref = do
           . queryItem "invitation_id" (toByteString' ref)
       )
   let lbs = fromMaybe "" $ responseBody r
-  return $ fromByteString . fromMaybe (error "No code?") $ encodeUtf8 <$> (lbs ^? key "code" . _String)
+  pure $ fromByteString (maybe (error "No code?") encodeUtf8 (lbs ^? key "code" . _String))
 
 -- | Create a SCIM token.
 createToken_ ::
diff --git a/services/brig/test/integration/Federation/End2end.hs b/services/brig/test/integration/Federation/End2end.hs
index 3f7ad9d58b..9e11e07d72 100644
--- a/services/brig/test/integration/Federation/End2end.hs
+++ b/services/brig/test/integration/Federation/End2end.hs
@@ -498,7 +498,7 @@ testSendMessage brig1 brig2 galley2 cannon1 = do
       <$> addClient
         brig1
         (userId alice)
-        (defNewClient PermanentClientType [] (someLastPrekeys !! 0))
+        (defNewClient PermanentClientType [] (Imports.head someLastPrekeys))
 
   -- create bob user and client on domain 2
   bob <- randomUser brig2
@@ -523,7 +523,7 @@ testSendMessage brig1 brig2 galley2 cannon1 = do
       rcpts = [(userQualifiedId alice, aliceClient, msgText)]
       msg = mkQualifiedOtrPayload bobClient rcpts "" MismatchReportAll
 
-  WS.bracketR cannon1 (userId alice) $ \(wsAlice) -> do
+  WS.bracketR cannon1 (userId alice) $ \wsAlice -> do
     post
       ( galley2
           . paths
@@ -562,7 +562,7 @@ testSendMessageToRemoteConv brig1 brig2 galley1 galley2 cannon1 = do
   alice <- randomUser brig1
   aliceClient <-
     fmap clientId . responseJsonError
-      =<< addClient brig1 (userId alice) (defNewClient PermanentClientType [] (someLastPrekeys !! 0))
+      =<< addClient brig1 (userId alice) (defNewClient PermanentClientType [] (Imports.head someLastPrekeys))
       <!! const 201 === statusCode
 
   -- create bob user and client on domain 2
@@ -586,7 +586,7 @@ testSendMessageToRemoteConv brig1 brig2 galley1 galley2 cannon1 = do
       rcpts = [(userQualifiedId alice, aliceClient, msgText)]
       msg = mkQualifiedOtrPayload bobClient rcpts "" MismatchReportAll
 
-  WS.bracketR cannon1 (userId alice) $ \(wsAlice) -> do
+  WS.bracketR cannon1 (userId alice) $ \wsAlice -> do
     post
       ( galley2
           . paths
diff --git a/services/brig/test/integration/Federation/Util.hs b/services/brig/test/integration/Federation/Util.hs
index 9131cd1fa7..a78bf654a7 100644
--- a/services/brig/test/integration/Federation/Util.hs
+++ b/services/brig/test/integration/Federation/Util.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE PartialTypeSignatures #-}
-{-# LANGUAGE QuasiQuotes #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
 {-# OPTIONS_GHC -Wno-partial-type-signatures #-}
 {-# OPTIONS_GHC -Wno-unused-imports #-}
diff --git a/services/brig/test/integration/Index/Create.hs b/services/brig/test/integration/Index/Create.hs
index 1b703647a3..686af9e33f 100644
--- a/services/brig/test/integration/Index/Create.hs
+++ b/services/brig/test/integration/Index/Create.hs
@@ -51,7 +51,7 @@ testCreateIndexWhenNotPresent brigOpts = do
   case parseURI strictURIParserOptions (Text.encodeUtf8 esURL) of
     Left e -> fail $ "Invalid ES URL: " <> show esURL <> "\nerror: " <> show e
     Right esURI -> do
-      indexName <- ES.IndexName . Text.pack <$> (replicateM 20 $ Random.randomRIO ('a', 'z'))
+      indexName <- ES.IndexName . Text.pack <$> replicateM 20 (Random.randomRIO ('a', 'z'))
       let replicas = 2
           shards = 2
           refreshInterval = 5
@@ -59,7 +59,7 @@ testCreateIndexWhenNotPresent brigOpts = do
             IndexOpts.localElasticSettings
               & IndexOpts.esServer .~ esURI
               & IndexOpts.esIndex .~ indexName
-              & IndexOpts.esIndexReplicas .~ (ES.ReplicaCount replicas)
+              & IndexOpts.esIndexReplicas .~ ES.ReplicaCount replicas
               & IndexOpts.esIndexShardCount .~ shards
               & IndexOpts.esIndexRefreshInterval .~ refreshInterval
       devNullLogger <- Log.create (Log.Path "/dev/null")
@@ -83,7 +83,7 @@ testCreateIndexWhenPresent brigOpts = do
   case parseURI strictURIParserOptions (Text.encodeUtf8 esURL) of
     Left e -> fail $ "Invalid ES URL: " <> show esURL <> "\nerror: " <> show e
     Right esURI -> do
-      indexName <- ES.IndexName . Text.pack <$> (replicateM 20 $ Random.randomRIO ('a', 'z'))
+      indexName <- ES.IndexName . Text.pack <$> replicateM 20 (Random.randomRIO ('a', 'z'))
       ES.withBH HTTP.defaultManagerSettings (ES.Server esURL) $ do
         _ <- ES.createIndex (ES.IndexSettings (ES.ShardCount 1) (ES.ReplicaCount 1)) indexName
         indexExists <- ES.indexExists indexName
@@ -96,7 +96,7 @@ testCreateIndexWhenPresent brigOpts = do
             IndexOpts.localElasticSettings
               & IndexOpts.esServer .~ esURI
               & IndexOpts.esIndex .~ indexName
-              & IndexOpts.esIndexReplicas .~ (ES.ReplicaCount replicas)
+              & IndexOpts.esIndexReplicas .~ ES.ReplicaCount replicas
               & IndexOpts.esIndexShardCount .~ shards
               & IndexOpts.esIndexRefreshInterval .~ refreshInterval
       devNullLogger <- Log.create (Log.Path "/dev/null")
diff --git a/services/brig/test/integration/Main.hs b/services/brig/test/integration/Main.hs
index e39c075e45..586273d439 100644
--- a/services/brig/test/integration/Main.hs
+++ b/services/brig/test/integration/Main.hs
@@ -117,9 +117,9 @@ runTests iConf brigOpts otherArgs = do
         Opts.TurnSourceFiles files -> files
         Opts.TurnSourceDNS _ -> error "The integration tests can only be run when TurnServers are sourced from files"
       localDomain = brigOpts ^. Opts.optionSettings . Opts.federationDomain
-      casHost = (\v -> (Opts.cassandra v) ^. casEndpoint . epHost) brigOpts
-      casPort = (\v -> (Opts.cassandra v) ^. casEndpoint . epPort) brigOpts
-      casKey = (\v -> (Opts.cassandra v) ^. casKeyspace) brigOpts
+      casHost = (\v -> Opts.cassandra v ^. casEndpoint . epHost) brigOpts
+      casPort = (\v -> Opts.cassandra v ^. casEndpoint . epPort) brigOpts
+      casKey = (\v -> Opts.cassandra v ^. casKeyspace) brigOpts
       awsOpts = Opts.aws brigOpts
   lg <- Logger.new Logger.defSettings -- TODO: use mkLogger'?
   db <- defInitCassandra casKey casHost casPort lg
@@ -176,8 +176,8 @@ runTests iConf brigOpts otherArgs = do
 
     parseEmailAWSOpts :: IO (Maybe Opts.EmailAWSOpts)
     parseEmailAWSOpts = case Opts.email . Opts.emailSMS $ brigOpts of
-      (Opts.EmailAWS aws) -> return (Just aws)
-      (Opts.EmailSMTP _) -> return Nothing
+      (Opts.EmailAWS aws) -> pure (Just aws)
+      (Opts.EmailSMTP _) -> pure Nothing
 
 main :: IO ()
 main = withOpenSSL $ do
@@ -187,8 +187,8 @@ main = withOpenSSL $ do
   let configArgs = getConfigArgs args
   let otherArgs = args \\ configArgs
   (iPath, bPath) <- withArgs configArgs parseConfigPaths
-  iConf <- join $ handleParseError <$> decodeFileEither iPath
-  bConf <- join $ handleParseError <$> decodeFileEither bPath
+  iConf <- handleParseError =<< decodeFileEither iPath
+  bConf <- handleParseError =<< decodeFileEither bPath
   brigOpts <- maybe (fail "failed to parse brig options file") pure bConf
   integrationConfig <- maybe (fail "failed to parse integration.yaml file") pure iConf
   runTests integrationConfig brigOpts otherArgs
@@ -211,17 +211,17 @@ parseConfigPaths = do
     pathParser :: Parser (String, String)
     pathParser =
       (,)
-        <$> ( strOption $
-                long "integration-config"
-                  <> short 'i'
-                  <> help "Integration config to load"
-                  <> showDefault
-                  <> value defaultIntPath
-            )
-        <*> ( strOption $
-                long "service-config"
-                  <> short 's'
-                  <> help "Brig application config to load"
-                  <> showDefault
-                  <> value defaultBrigPath
-            )
+        <$> strOption
+          ( long "integration-config"
+              <> short 'i'
+              <> help "Integration config to load"
+              <> showDefault
+              <> value defaultIntPath
+          )
+        <*> strOption
+          ( long "service-config"
+              <> short 's'
+              <> help "Brig application config to load"
+              <> showDefault
+              <> value defaultBrigPath
+          )
diff --git a/services/brig/test/integration/Util.hs b/services/brig/test/integration/Util.hs
index ef7894df17..a6f8138f15 100644
--- a/services/brig/test/integration/Util.hs
+++ b/services/brig/test/integration/Util.hs
@@ -190,7 +190,7 @@ instance ToJSON SESNotification where
       [ "notificationType" .= ("Bounce" :: Text),
         "bounce"
           .= object
-            [ "bouncedRecipients" .= (fmap (\e -> object ["emailAddress" .= e]) ems),
+            [ "bouncedRecipients" .= fmap (\e -> object ["emailAddress" .= e]) ems,
               "bounceType" .= typ
             ]
       ]
@@ -199,7 +199,7 @@ instance ToJSON SESNotification where
       [ "notificationType" .= ("Complaint" :: Text),
         "complaint"
           .= object
-            [ "complainedRecipients" .= (fmap (\e -> object ["emailAddress" .= e]) ems)
+            [ "complainedRecipients" .= fmap (\e -> object ["emailAddress" .= e]) ems
             ]
       ]
 
@@ -322,13 +322,13 @@ getActivationCode brig ep = do
   let lbs = fromMaybe "" $ responseBody r
   let akey = ActivationKey . Ascii.unsafeFromText <$> (lbs ^? key "key" . _String)
   let acode = ActivationCode . Ascii.unsafeFromText <$> (lbs ^? key "code" . _String)
-  return $ (,) <$> akey <*> acode
+  pure $ (,) <$> akey <*> acode
 
 getPhoneLoginCode :: Brig -> Phone -> Http (Maybe LoginCode)
 getPhoneLoginCode brig p = do
   r <- get $ brig . path "/i/users/login-code" . queryItem "phone" (toByteString' p)
   let lbs = fromMaybe "" $ responseBody r
-  return (LoginCode <$> (lbs ^? key "code" . _String))
+  pure (LoginCode <$> (lbs ^? key "code" . _String))
 
 assertUpdateNotification :: WS.WebSocket -> UserId -> UserUpdate -> IO Notification
 assertUpdateNotification ws uid upd = WS.assertMatch (5 # Second) ws $ \n -> do
@@ -411,12 +411,12 @@ postUserWithEmail hasPassword validateBody name email havePhone ssoid teamid bri
 postUserInternal :: Object -> Brig -> Http User
 postUserInternal payload brig = do
   rs <- post (brig . path "/i/users" . contentJson . body (RequestBodyLBS $ encode payload)) <!! const 201 === statusCode
-  maybe (error $ "postUserInternal: Failed to decode user due to: " ++ show rs) return (responseJsonMaybe rs)
+  maybe (error $ "postUserInternal: Failed to decode user due to: " ++ show rs) pure (responseJsonMaybe rs)
 
 postUserRegister :: Object -> Brig -> Http User
 postUserRegister payload brig = do
   rs <- postUserRegister' payload brig <!! const 201 === statusCode
-  maybe (error $ "postUserRegister: Failed to decode user due to: " ++ show rs) return (responseJsonMaybe rs)
+  maybe (error $ "postUserRegister: Failed to decode user due to: " ++ show rs) pure (responseJsonMaybe rs)
 
 postUserRegister' :: (MonadIO m, MonadCatch m, MonadHttp m) => Object -> Brig -> m ResponseLBS
 postUserRegister' payload brig = do
@@ -748,8 +748,8 @@ isMember g usr cnv = do
         . paths ["i", "conversations", toByteString' cnv, "members", toByteString' (tUnqualified usr)]
         . expect2xx
   case responseJsonMaybe res of
-    Nothing -> return False
-    Just m -> return (qUntagged usr == memId m)
+    Nothing -> pure False
+    Just m -> pure (qUntagged usr == memId m)
 
 getStatus :: HasCallStack => Brig -> UserId -> (MonadIO m, MonadHttp m) => m AccountStatus
 getStatus brig u =
@@ -802,7 +802,7 @@ mkEmailRandomLocalSuffix :: MonadIO m => Text -> m Email
 mkEmailRandomLocalSuffix e = do
   uid <- liftIO UUID.nextRandom
   case parseEmail e of
-    Just (Email loc dom) -> return $ Email (loc <> "+" <> UUID.toText uid) dom
+    Just (Email loc dom) -> pure $ Email (loc <> "+" <> UUID.toText uid) dom
     Nothing -> error $ "Invalid email address: " ++ Text.unpack e
 
 -- | Generate emails that are in the trusted whitelist of domains whose @+@ suffices count for email
@@ -825,7 +825,7 @@ randomPhone :: MonadIO m => m Phone
 randomPhone = liftIO $ do
   nrs <- map show <$> replicateM 14 (randomRIO (0, 9) :: IO Int)
   let phone = parsePhone . Text.pack $ "+0" ++ concat nrs
-  return $ fromMaybe (error "Invalid random phone#") phone
+  pure $ fromMaybe (error "Invalid random phone#") phone
 
 randomActivationCode :: (HasCallStack, MonadIO m) => m ActivationCode
 randomActivationCode =
@@ -938,7 +938,7 @@ randomBytes n = BS.pack <$> replicateM n randomIO
 randomHandle :: MonadIO m => m Text
 randomHandle = liftIO $ do
   nrs <- replicateM 21 (randomRIO (97, 122)) -- a-z
-  return (Text.pack (map chr nrs))
+  pure (Text.pack (map chr nrs))
 
 randomName :: MonadIO m => m Name
 randomName = randomNameWithMaxLen 128
@@ -956,9 +956,9 @@ randomNameWithMaxLen :: MonadIO m => Word -> m Name
 randomNameWithMaxLen maxLen = liftIO $ do
   len <- randomRIO (2, maxLen)
   chars <- fill len []
-  return $ Name (Text.pack chars)
+  pure $ Name (Text.pack chars)
   where
-    fill 0 chars = return chars
+    fill 0 chars = pure chars
     fill 1 chars = (: chars) <$> randLetter
     fill n chars = do
       c <- randChar
@@ -969,14 +969,14 @@ randomNameWithMaxLen maxLen = liftIO $ do
     randLetter = do
       c <- randChar
       if isLetter c
-        then return c
+        then pure c
         else randLetter
 
 retryWhileN :: (MonadIO m) => Int -> (a -> Bool) -> m a -> m a
 retryWhileN n f m =
   retrying
     (constantDelay 1000000 <> limitRetries n)
-    (const (return . f))
+    (const (pure . f))
     (const m)
 
 recoverN :: (MonadIO m, MonadMask m) => Int -> m a -> m a
@@ -1036,7 +1036,7 @@ aFewTimes
     retrying
       (exponentialBackoff 1000 <> limitRetries retries)
       (\_ -> pure . not . good)
-      (\_ -> action)
+      (const action)
 
 assertOne :: (HasCallStack, MonadIO m, Show a) => [a] -> m a
 assertOne [a] = pure a
diff --git a/services/brig/test/integration/Util/AWS.hs b/services/brig/test/integration/Util/AWS.hs
index 92a3d8e687..8e10d0cfea 100644
--- a/services/brig/test/integration/Util/AWS.hs
+++ b/services/brig/test/integration/Util/AWS.hs
@@ -109,7 +109,7 @@ assertUserId :: String -> UserId -> PU.UserEvent -> IO ()
 assertUserId l uid ev = assertEqual (l <> "userId") uid (Id $ fromMaybe (error "failed to decode userId") $ UUID.fromByteString $ Lazy.fromStrict (ev ^. PU.userId))
 
 assertTeamId :: String -> Maybe TeamId -> PU.UserEvent -> IO ()
-assertTeamId l (Just tid) ev = assertEqual (l <> "teamId should exist") tid (Id . fromMaybe (error "failed to parse teamId") . join $ fmap (UUID.fromByteString . Lazy.fromStrict) (ev ^? PU.teamId))
+assertTeamId l (Just tid) ev = assertEqual (l <> "teamId should exist") tid ((Id . fromMaybe (error "failed to parse teamId")) ((UUID.fromByteString . Lazy.fromStrict) =<< (ev ^? PU.teamId)))
 assertTeamId l Nothing ev = assertEqual (l <> "teamId should not exist") Nothing (ev ^. PU.maybe'teamId)
 
 assertName :: String -> Maybe Name -> PU.UserEvent -> IO ()