diff --git a/bridges/modules/shift-session-manager/src/lib.rs b/bridges/modules/shift-session-manager/src/lib.rs
index 3635e6223d7f..2ff6a1397460 100644
--- a/bridges/modules/shift-session-manager/src/lib.rs
+++ b/bridges/modules/shift-session-manager/src/lib.rs
@@ -19,7 +19,7 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
-use frame_support::{decl_module, decl_storage};
+use frame_support::{decl_module, decl_storage, WeakBoundedVec};
 use sp_std::prelude::*;
 
 /// The module configuration trait.
@@ -37,13 +37,17 @@ decl_storage! {
 	}
 }
 
-impl<T: Config> pallet_session::SessionManager<T::ValidatorId> for Pallet<T> {
+impl<T: Config> pallet_session::SessionManager<T::ValidatorId, T::MaxValidatorsCount>
+	for Pallet<T>
+{
 	fn end_session(_: sp_staking::SessionIndex) {}
 	fn start_session(_: sp_staking::SessionIndex) {}
-	fn new_session(session_index: sp_staking::SessionIndex) -> Option<Vec<T::ValidatorId>> {
+	fn new_session(
+		session_index: sp_staking::SessionIndex,
+	) -> Option<WeakBoundedVec<T::ValidatorId, T::MaxValidatorsCount>> {
 		// we don't want to add even more fields to genesis config => just return None
 		if session_index == 0 || session_index == 1 {
-			return None;
+			return None
 		}
 
 		// the idea that on first call (i.e. when session 1 ends) we're reading current
@@ -66,7 +70,7 @@ impl<T: Config> Pallet<T> {
 	fn select_validators(
 		session_index: sp_staking::SessionIndex,
 		available_validators: &[T::ValidatorId],
-	) -> Vec<T::ValidatorId> {
+	) -> WeakBoundedVec<T::ValidatorId, T::MaxValidatorsCount> {
 		let available_validators_count = available_validators.len();
 		let count = sp_std::cmp::max(1, 2 * available_validators_count / 3);
 		let offset = session_index as usize % available_validators_count;
@@ -80,7 +84,10 @@ impl<T: Config> Pallet<T> {
 			_ => available_validators[offset..end].to_vec(),
 		};
 
-		session_validators
+		WeakBoundedVec::force_from(
+			session_validators,
+			Some("select_validators: too many validators"),
+		)
 	}
 }
 
@@ -90,13 +97,17 @@ mod tests {
 	#![allow(clippy::from_over_into)]
 
 	use super::*;
-	use frame_support::sp_io::TestExternalities;
-	use frame_support::sp_runtime::{
-		testing::{Header, UintAuthorityId},
-		traits::{BlakeTwo256, ConvertInto, IdentityLookup},
-		Perbill, RuntimeAppPublic,
+	use frame_support::{
+		parameter_types,
+		sp_io::TestExternalities,
+		sp_runtime::{
+			testing::{Header, UintAuthorityId},
+			traits::{BlakeTwo256, ConvertInto, IdentityLookup},
+			Perbill, RuntimeAppPublic,
+		},
+		weights::Weight,
+		BasicExternalities,
 	};
-	use frame_support::{parameter_types, weights::Weight, BasicExternalities};
 	use sp_core::H256;
 
 	type AccountId = u64;
@@ -171,17 +182,21 @@ mod tests {
 	impl pallet_session::SessionHandler<AccountId> for TestSessionHandler {
 		const KEY_TYPE_IDS: &'static [sp_runtime::KeyTypeId] = &[UintAuthorityId::ID];
 
-		fn on_genesis_session<Ks: sp_runtime::traits::OpaqueKeys>(_validators: &[(AccountId, Ks)]) {}
+		fn on_genesis_session<Ks: sp_runtime::traits::OpaqueKeys>(_validators: &[(AccountId, Ks)]) {
+		}
 
-		fn on_new_session<Ks: sp_runtime::traits::OpaqueKeys>(_: bool, _: &[(AccountId, Ks)], _: &[(AccountId, Ks)]) {}
+		fn on_new_session<Ks: sp_runtime::traits::OpaqueKeys>(
+			_: bool,
+			_: &[(AccountId, Ks)],
+			_: &[(AccountId, Ks)],
+		) {
+		}
 
 		fn on_disabled(_: u32) {}
 	}
 
 	fn new_test_ext() -> TestExternalities {
-		let mut t = frame_system::GenesisConfig::default()
-			.build_storage::<TestRuntime>()
-			.unwrap();
+		let mut t = frame_system::GenesisConfig::default().build_storage::<TestRuntime>().unwrap();
 
 		let keys = vec![
 			(1, 1, UintAuthorityId(1)),
diff --git a/runtime/common/src/elections.rs b/runtime/common/src/elections.rs
index ae0ec401f63a..0972053413e4 100644
--- a/runtime/common/src/elections.rs
+++ b/runtime/common/src/elections.rs
@@ -56,7 +56,6 @@ impl pallet_election_provider_multi_phase::BenchmarkingConfig for BenchmarkConfi
 	const DESIRED_TARGETS: [u32; 2] = [200, 400];
 	const SNAPSHOT_MAXIMUM_VOTERS: u32 = 1000;
 	const MINER_MAXIMUM_VOTERS: u32 = 1000;
-	const MAXIMUM_TARGETS: u32 = 300;
 }
 
 /// The accuracy type used for genesis election provider;
diff --git a/runtime/kusama/src/lib.rs b/runtime/kusama/src/lib.rs
index 4afe8488f93d..7c7c5bdc796a 100644
--- a/runtime/kusama/src/lib.rs
+++ b/runtime/kusama/src/lib.rs
@@ -266,7 +266,8 @@ impl pallet_babe::Config for Runtime {
 
 	type WeightInfo = ();
 
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -361,10 +362,12 @@ impl pallet_session::Config for Runtime {
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxKeysEncodingSize = MaxKeysEncodingSize;
 }
 
 impl pallet_session::historical::Config for Runtime {
-	type FullIdentification = pallet_staking::Exposure<AccountId, Balance>;
+	type FullIdentification = pallet_staking::Exposure<AccountId, Balance, MaxIndividualExposures>;
 	type FullIdentificationOf = pallet_staking::ExposureOf<Runtime>;
 }
 
@@ -434,6 +437,7 @@ impl pallet_election_provider_multi_phase::Config for Runtime {
 	>;
 	type WeightInfo = weights::pallet_election_provider_multi_phase::WeightInfo<Self>;
 	type VoterSnapshotPerBlock = VoterSnapshotPerBlock;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -516,7 +520,17 @@ parameter_types! {
 	pub const BondingDuration: pallet_staking::EraIndex = 28;
 	// 27 eras in which slashes can be cancelled (slightly less than 7 days).
 	pub const SlashDeferDuration: pallet_staking::EraIndex = 27;
-	pub const MaxNominatorRewardedPerValidator: u32 = 256;
+	pub const MaxRewardableIndividualExposures: u32 = 256;
+	pub const MaxIndividualExposures: u32 = 10_000;
+	pub const MaxNominations: u32 = <NposCompactSolution24 as sp_npos_elections::NposSolution>::LIMIT as u32;
+	pub const MaxUnappliedSlashes: u32 = 1_000;
+	pub const MaxInvulnerablesCount: u32 = 10;
+	pub const MaxHistoryDepth: u32 = 10_000;
+	pub const MaxReportersCount: u32 = 1_000;
+	pub const MaxPriorSlashingSpans: u32 = 1_000;
+	pub const MaxValidatorsCount: u32 = 4_000;
+	pub const MaxKeysEncodingSize: u32 = 1_000;
+	pub const MaxUnlockingChunks: u32 = 32;
 	pub const OffendingValidatorsThreshold: Perbill = Perbill::from_percent(17);
 }
 
@@ -529,11 +543,11 @@ type SlashCancelOrigin = EnsureOneOf<
 impl frame_election_provider_support::onchain::Config for Runtime {
 	type Accuracy = runtime_common::elections::OnOnChainAccuracy;
 	type DataProvider = Staking;
+	type MaxNominations = MaxNominations;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 impl pallet_staking::Config for Runtime {
-	const MAX_NOMINATIONS: u32 =
-		<NposCompactSolution24 as sp_npos_elections::NposSolution>::LIMIT as u32;
 	type Currency = Balances;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = CurrencyToVote;
@@ -551,7 +565,16 @@ impl pallet_staking::Config for Runtime {
 	type SessionInterface = Self;
 	type EraPayout = EraPayout;
 	type NextNewSession = Session;
-	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
+	type MaxRewardableIndividualExposures = MaxRewardableIndividualExposures;
+	type MaxIndividualExposures = MaxIndividualExposures;
+	type MaxNominations = MaxNominations;
+	type MaxUnappliedSlashes = MaxUnappliedSlashes;
+	type MaxInvulnerablesCount = MaxInvulnerablesCount;
+	type MaxHistoryDepth = MaxHistoryDepth;
+	type MaxReportersCount = MaxReportersCount;
+	type MaxPriorSlashingSpans = MaxPriorSlashingSpans;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxUnlockingChunks = MaxUnlockingChunks;
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	// Use the nominators map to iter voters, but also keep bags-list up-to-date.
 	type SortedListProvider = runtime_common::elections::UseNominatorsAndUpdateBagsList<Runtime>;
@@ -728,8 +751,6 @@ parameter_types! {
 	pub const BountyCuratorDeposit: Permill = Permill::from_percent(50);
 	pub const BountyValueMinimum: Balance = 200 * CENTS;
 	pub const MaxApprovals: u32 = 100;
-	pub const MaxAuthorities: u32 = 100_000;
-	pub const MaxKeys: u32 = 10_000;
 	pub const MaxPeerInHeartbeats: u32 = 10_000;
 	pub const MaxPeerDataEncodingSize: u32 = 1_000;
 }
@@ -784,10 +805,11 @@ impl pallet_offences::Config for Runtime {
 	type Event = Event;
 	type IdentificationTuple = pallet_session::historical::IdentificationTuple<Self>;
 	type OnOffenceHandler = Staking;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_authority_discovery::Config for Runtime {
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -804,9 +826,10 @@ impl pallet_im_online::Config for Runtime {
 	type ReportUnresponsiveness = Offences;
 	type UnsignedPriority = ImOnlineUnsignedPriority;
 	type WeightInfo = weights::pallet_im_online::WeightInfo<Runtime>;
-	type MaxKeys = MaxKeys;
+	type MaxKeys = MaxValidatorsCount;
 	type MaxPeerInHeartbeats = MaxPeerInHeartbeats;
 	type MaxPeerDataEncodingSize = MaxPeerDataEncodingSize;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_grandpa::Config for Runtime {
@@ -830,7 +853,8 @@ impl pallet_grandpa::Config for Runtime {
 	>;
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 /// Submits transaction with the node's public and signature type. Adheres to the signed extension
diff --git a/runtime/kusama/src/tests.rs b/runtime/kusama/src/tests.rs
index d2c1c725e3a9..e3a59607de99 100644
--- a/runtime/kusama/src/tests.rs
+++ b/runtime/kusama/src/tests.rs
@@ -49,7 +49,7 @@ fn sample_size_is_sensible() {
 fn payout_weight_portion() {
 	use pallet_staking::WeightInfo;
 	let payout_weight = <Runtime as pallet_staking::Config>::WeightInfo::payout_stakers_alive_staked(
-		MaxNominatorRewardedPerValidator::get(),
+		MaxRewardableIndividualExposures::get(),
 	) as f64;
 	let block_weight = BlockWeights::get().max_block as f64;
 
diff --git a/runtime/kusama/src/weights/pallet_staking.rs b/runtime/kusama/src/weights/pallet_staking.rs
index 5f385be7167e..7092e73a742b 100644
--- a/runtime/kusama/src/weights/pallet_staking.rs
+++ b/runtime/kusama/src/weights/pallet_staking.rs
@@ -111,7 +111,6 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking MinValidatorBond (r:1 w:0)
 	// Storage: Staking Validators (r:1 w:1)
-	// Storage: Staking MaxValidatorsCount (r:1 w:0)
 	// Storage: Staking Nominators (r:1 w:1)
 	// Storage: Staking CounterForNominators (r:1 w:1)
 	// Storage: BagsList ListNodes (r:2 w:2)
@@ -120,7 +119,7 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	// Storage: Staking CounterForValidators (r:1 w:1)
 	fn validate() -> Weight {
 		(63_555_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(11 as Weight))
+			.saturating_add(T::DbWeight::get().reads(10 as Weight))
 			.saturating_add(T::DbWeight::get().writes(8 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
@@ -386,13 +385,12 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: Staking MinValidatorBond (r:0 w:1)
-	// Storage: Staking MaxValidatorsCount (r:0 w:1)
 	// Storage: Staking ChillThreshold (r:0 w:1)
 	// Storage: Staking MaxNominatorsCount (r:0 w:1)
 	// Storage: Staking MinNominatorBond (r:0 w:1)
 	fn set_staking_limits() -> Weight {
 		(5_996_000 as Weight)
-			.saturating_add(T::DbWeight::get().writes(5 as Weight))
+			.saturating_add(T::DbWeight::get().writes(4 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking ChillThreshold (r:1 w:0)
diff --git a/runtime/polkadot/src/lib.rs b/runtime/polkadot/src/lib.rs
index 88e8820c5803..51e2e31abc19 100644
--- a/runtime/polkadot/src/lib.rs
+++ b/runtime/polkadot/src/lib.rs
@@ -297,7 +297,8 @@ impl pallet_babe::Config for Runtime {
 
 	type WeightInfo = ();
 
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -388,10 +389,12 @@ impl pallet_session::Config for Runtime {
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxKeysEncodingSize = MaxKeysEncodingSize;
 }
 
 impl pallet_session::historical::Config for Runtime {
-	type FullIdentification = pallet_staking::Exposure<AccountId, Balance>;
+	type FullIdentification = pallet_staking::Exposure<AccountId, Balance, MaxIndividualExposures>;
 	type FullIdentificationOf = pallet_staking::ExposureOf<Runtime>;
 }
 
@@ -463,6 +466,7 @@ impl pallet_election_provider_multi_phase::Config for Runtime {
 	>;
 	type WeightInfo = weights::pallet_election_provider_multi_phase::WeightInfo<Self>;
 	type VoterSnapshotPerBlock = VoterSnapshotPerBlock;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -499,7 +503,17 @@ parameter_types! {
 	pub const BondingDuration: pallet_staking::EraIndex = 28;
 	pub const SlashDeferDuration: pallet_staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
-	pub const MaxNominatorRewardedPerValidator: u32 = 256;
+	pub const MaxRewardableIndividualExposures: u32 = 256;
+	pub const MaxIndividualExposures: u32 = 10_000;
+	pub const MaxNominations: u32 = <NposCompactSolution16 as sp_npos_elections::NposSolution>::LIMIT as u32;
+	pub const MaxUnappliedSlashes: u32 = 1_000;
+	pub const MaxInvulnerablesCount: u32 = 10;
+	pub const MaxHistoryDepth: u32 = 10_000;
+	pub const MaxReportersCount: u32 = 1_000;
+	pub const MaxPriorSlashingSpans: u32 = 1_000;
+	pub const MaxValidatorsCount: u32 = 4_000;
+	pub const MaxKeysEncodingSize: u32 = 1_000;
+	pub const MaxUnlockingChunks: u32 = 32;
 	pub const OffendingValidatorsThreshold: Perbill = Perbill::from_percent(17);
 }
 
@@ -512,11 +526,11 @@ type SlashCancelOrigin = EnsureOneOf<
 impl frame_election_provider_support::onchain::Config for Runtime {
 	type Accuracy = runtime_common::elections::OnOnChainAccuracy;
 	type DataProvider = Staking;
+	type MaxTargets = MaxValidatorsCount;
+	type MaxNominations = MaxNominations;
 }
 
 impl pallet_staking::Config for Runtime {
-	const MAX_NOMINATIONS: u32 =
-		<NposCompactSolution16 as sp_npos_elections::NposSolution>::LIMIT as u32;
 	type Currency = Balances;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = CurrencyToVote;
@@ -531,7 +545,16 @@ impl pallet_staking::Config for Runtime {
 	type SlashCancelOrigin = SlashCancelOrigin;
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
-	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
+	type MaxRewardableIndividualExposures = MaxRewardableIndividualExposures;
+	type MaxIndividualExposures = MaxIndividualExposures;
+	type MaxNominations = MaxNominations;
+	type MaxUnappliedSlashes = MaxUnappliedSlashes;
+	type MaxInvulnerablesCount = MaxInvulnerablesCount;
+	type MaxHistoryDepth = MaxHistoryDepth;
+	type MaxReportersCount = MaxReportersCount;
+	type MaxPriorSlashingSpans = MaxPriorSlashingSpans;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxUnlockingChunks = MaxUnlockingChunks;
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	type NextNewSession = Session;
 	type ElectionProvider = ElectionProviderMultiPhase;
@@ -751,8 +774,6 @@ parameter_types! {
 	pub const BountyCuratorDeposit: Permill = Permill::from_percent(50);
 	pub const BountyValueMinimum: Balance = 10 * DOLLARS;
 	pub const MaxApprovals: u32 = 100;
-	pub const MaxAuthorities: u32 = 100_000;
-	pub const MaxKeys: u32 = 10_000;
 	pub const MaxPeerInHeartbeats: u32 = 10_000;
 	pub const MaxPeerDataEncodingSize: u32 = 1_000;
 }
@@ -807,10 +828,11 @@ impl pallet_offences::Config for Runtime {
 	type Event = Event;
 	type IdentificationTuple = pallet_session::historical::IdentificationTuple<Self>;
 	type OnOffenceHandler = Staking;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_authority_discovery::Config for Runtime {
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -827,9 +849,10 @@ impl pallet_im_online::Config for Runtime {
 	type ReportUnresponsiveness = Offences;
 	type UnsignedPriority = ImOnlineUnsignedPriority;
 	type WeightInfo = weights::pallet_im_online::WeightInfo<Runtime>;
-	type MaxKeys = MaxKeys;
+	type MaxKeys = MaxValidatorsCount;
 	type MaxPeerInHeartbeats = MaxPeerInHeartbeats;
 	type MaxPeerDataEncodingSize = MaxPeerDataEncodingSize;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_grandpa::Config for Runtime {
@@ -853,7 +876,8 @@ impl pallet_grandpa::Config for Runtime {
 	>;
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 /// Submits a transaction with the node's public and signature type. Adheres to the signed extension
@@ -1876,7 +1900,7 @@ mod test_fees {
 		use pallet_staking::WeightInfo;
 		let payout_weight =
 			<Runtime as pallet_staking::Config>::WeightInfo::payout_stakers_alive_staked(
-				MaxNominatorRewardedPerValidator::get(),
+				MaxRewardableIndividualExposures::get(),
 			) as f64;
 		let block_weight = BlockWeights::get().max_block as f64;
 
diff --git a/runtime/polkadot/src/weights/pallet_staking.rs b/runtime/polkadot/src/weights/pallet_staking.rs
index 2e30aabcbf09..f67a33b0c8b4 100644
--- a/runtime/polkadot/src/weights/pallet_staking.rs
+++ b/runtime/polkadot/src/weights/pallet_staking.rs
@@ -105,13 +105,12 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking MinValidatorBond (r:1 w:0)
 	// Storage: Staking Validators (r:1 w:1)
-	// Storage: Staking MaxValidatorsCount (r:1 w:0)
 	// Storage: Staking Nominators (r:1 w:1)
 	// Storage: Staking CounterForNominators (r:1 w:1)
 	// Storage: Staking CounterForValidators (r:1 w:1)
 	fn validate() -> Weight {
 		(36_901_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(7 as Weight))
+			.saturating_add(T::DbWeight::get().reads(6 as Weight))
 			.saturating_add(T::DbWeight::get().writes(4 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
@@ -364,13 +363,12 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: Staking MinValidatorBond (r:0 w:1)
-	// Storage: Staking MaxValidatorsCount (r:0 w:1)
 	// Storage: Staking ChillThreshold (r:0 w:1)
 	// Storage: Staking MaxNominatorsCount (r:0 w:1)
 	// Storage: Staking MinNominatorBond (r:0 w:1)
 	fn set_staking_limits() -> Weight {
 		(5_680_000 as Weight)
-			.saturating_add(T::DbWeight::get().writes(5 as Weight))
+			.saturating_add(T::DbWeight::get().writes(4 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking ChillThreshold (r:1 w:0)
diff --git a/runtime/rococo/src/lib.rs b/runtime/rococo/src/lib.rs
index d4f3ce524087..aa64f733e9fa 100644
--- a/runtime/rococo/src/lib.rs
+++ b/runtime/rococo/src/lib.rs
@@ -382,9 +382,9 @@ parameter_types! {
 
 parameter_types! {
 	pub const ImOnlineUnsignedPriority: TransactionPriority = TransactionPriority::max_value();
-	pub const MaxKeys: u32 = 10_000;
 	pub const MaxPeerInHeartbeats: u32 = 10_000;
 	pub const MaxPeerDataEncodingSize: u32 = 1_000;
+	pub const MaxReportersCount: u32 = 1_000;
 }
 
 impl pallet_im_online::Config for Runtime {
@@ -395,9 +395,10 @@ impl pallet_im_online::Config for Runtime {
 	type ReportUnresponsiveness = Offences;
 	type UnsignedPriority = ImOnlineUnsignedPriority;
 	type WeightInfo = ();
-	type MaxKeys = MaxKeys;
+	type MaxKeys = MaxValidatorsCount;
 	type MaxPeerInHeartbeats = MaxPeerInHeartbeats;
 	type MaxPeerDataEncodingSize = MaxPeerDataEncodingSize;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -428,17 +429,17 @@ where
 
 parameter_types! {
 	pub const MaxRetries: u32 = 3;
-	pub const MaxAuthorities: u32 = 100_000;
 }
 
 impl pallet_offences::Config for Runtime {
 	type Event = Event;
 	type IdentificationTuple = pallet_session::historical::IdentificationTuple<Self>;
 	type OnOffenceHandler = ();
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_authority_discovery::Config for Runtime {
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -456,6 +457,8 @@ parameter_types! {
 	/// This value increases the priority of `Operational` transactions by adding
 	/// a "virtual tip" that's equal to the `OperationalFeeMultiplier * final_fee`.
 	pub const OperationalFeeMultiplier: u8 = 5;
+	pub const MaxValidatorsCount: u32 = 4_000;
+	pub const MaxKeysEncodingSize: u32 = 1_000;
 }
 
 impl pallet_transaction_payment::Config for Runtime {
@@ -483,6 +486,8 @@ impl pallet_session::Config for Runtime {
 	type SessionManager = pallet_session::historical::NoteHistoricalRoot<Self, ValidatorManager>;
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxKeysEncodingSize = MaxKeysEncodingSize;
 	type WeightInfo = ();
 }
 
@@ -517,7 +522,8 @@ impl pallet_babe::Config for Runtime {
 
 	type WeightInfo = ();
 
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -557,7 +563,8 @@ impl pallet_grandpa::Config for Runtime {
 	>;
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -1083,8 +1090,9 @@ impl InstanceFilter<Call> for ProxyType {
 	fn filter(&self, c: &Call) -> bool {
 		match self {
 			ProxyType::Any => true,
-			ProxyType::CancelProxy =>
-				matches!(c, Call::Proxy(pallet_proxy::Call::reject_announcement { .. })),
+			ProxyType::CancelProxy => {
+				matches!(c, Call::Proxy(pallet_proxy::Call::reject_announcement { .. }))
+			},
 			ProxyType::Auction => matches!(
 				c,
 				Call::Auctions { .. } |
diff --git a/runtime/rococo/src/validator_manager.rs b/runtime/rococo/src/validator_manager.rs
index 763d12c73f5c..8892a3689fb4 100644
--- a/runtime/rococo/src/validator_manager.rs
+++ b/runtime/rococo/src/validator_manager.rs
@@ -16,7 +16,9 @@
 
 //! A pallet for managing validators on Rococo.
 
-use frame_support::{decl_error, decl_event, decl_module, decl_storage, traits::EnsureOrigin};
+use frame_support::{
+	decl_error, decl_event, decl_module, decl_storage, traits::EnsureOrigin, WeakBoundedVec,
+};
 use sp_staking::SessionIndex;
 use sp_std::vec::Vec;
 
@@ -93,14 +95,19 @@ decl_module! {
 
 impl<T: Config> Module<T> {}
 
-impl<T: Config> pallet_session::SessionManager<T::ValidatorId> for Module<T> {
-	fn new_session(new_index: SessionIndex) -> Option<Vec<T::ValidatorId>> {
+impl<T: Config> pallet_session::SessionManager<T::ValidatorId, T::MaxValidatorsCount>
+	for Module<T>
+{
+	fn new_session(
+		new_index: SessionIndex,
+	) -> Option<WeakBoundedVec<T::ValidatorId, T::MaxValidatorsCount>> {
 		if new_index <= 1 {
 			return None
 		}
 
 		let mut validators = Session::<T>::validators();
 
+		// It's crucial to remove validators first and then add for the WeakBoundedVec not to overflow
 		ValidatorsToRetire::<T>::take().iter().for_each(|v| {
 			if let Some(pos) = validators.iter().position(|r| r == v) {
 				validators.swap_remove(pos);
@@ -109,7 +116,12 @@ impl<T: Config> pallet_session::SessionManager<T::ValidatorId> for Module<T> {
 
 		ValidatorsToAdd::<T>::take().into_iter().for_each(|v| {
 			if !validators.contains(&v) {
-				validators.push(v);
+				if validators.try_push(v).is_err() {
+					log::error!(
+						target: "Validator Managers",
+						"new_session: Too many validators to add, will be truncated"
+					);
+				};
 			}
 		});
 
@@ -121,17 +133,22 @@ impl<T: Config> pallet_session::SessionManager<T::ValidatorId> for Module<T> {
 	fn start_session(_start_index: SessionIndex) {}
 }
 
-impl<T: Config> pallet_session::historical::SessionManager<T::ValidatorId, ()> for Module<T> {
-	fn new_session(new_index: SessionIndex) -> Option<Vec<(T::ValidatorId, ())>> {
-		<Self as pallet_session::SessionManager<_>>::new_session(new_index)
-			.map(|r| r.into_iter().map(|v| (v, Default::default())).collect())
+impl<T: Config>
+	pallet_session::historical::SessionManager<T::ValidatorId, (), T::MaxValidatorsCount>
+	for Module<T>
+{
+	fn new_session(
+		new_index: SessionIndex,
+	) -> Option<WeakBoundedVec<(T::ValidatorId, ()), T::MaxValidatorsCount>> {
+		<Self as pallet_session::SessionManager<_, _>>::new_session(new_index)
+			.map(|r| r.map_collect(|v| (v, Default::default())))
 	}
 
 	fn start_session(start_index: SessionIndex) {
-		<Self as pallet_session::SessionManager<_>>::start_session(start_index)
+		<Self as pallet_session::SessionManager<_, _>>::start_session(start_index)
 	}
 
 	fn end_session(end_index: SessionIndex) {
-		<Self as pallet_session::SessionManager<_>>::end_session(end_index)
+		<Self as pallet_session::SessionManager<_, _>>::end_session(end_index)
 	}
 }
diff --git a/runtime/test-runtime/src/lib.rs b/runtime/test-runtime/src/lib.rs
index 773c50920c52..a2b86b954694 100644
--- a/runtime/test-runtime/src/lib.rs
+++ b/runtime/test-runtime/src/lib.rs
@@ -188,7 +188,8 @@ impl pallet_babe::Config for Runtime {
 	type HandleEquivocation = ();
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -282,11 +283,13 @@ impl pallet_session::Config for Runtime {
 	type SessionManager = Staking;
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxKeysEncodingSize = MaxKeysEncodingSize;
 	type WeightInfo = ();
 }
 
 impl pallet_session::historical::Config for Runtime {
-	type FullIdentification = pallet_staking::Exposure<AccountId, Balance>;
+	type FullIdentification = pallet_staking::Exposure<AccountId, Balance, MaxIndividualExposures>;
 	type FullIdentificationOf = pallet_staking::ExposureOf<Runtime>;
 }
 
@@ -309,18 +312,28 @@ parameter_types! {
 	// 27 eras in which slashes can be cancelled (a bit less than 7 days).
 	pub storage SlashDeferDuration: pallet_staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
-	pub storage MaxNominatorRewardedPerValidator: u32 = 64;
+	pub storage MaxRewardableIndividualExposures: u32 = 64;
+	pub const MaxIndividualExposures: u32 = 1_000;
 	pub storage OffendingValidatorsThreshold: Perbill = Perbill::from_percent(17);
-	pub const MaxAuthorities: u32 = 100_000;
+	pub const MaxNominations: u32 = 16;
+	pub const MaxUnappliedSlashes: u32 = 1_000;
+	pub const MaxInvulnerablesCount: u32 = 10;
+	pub const MaxHistoryDepth: u32 = 10_000;
+	pub const MaxReportersCount: u32 = 1_000;
+	pub const MaxPriorSlashingSpans: u32 = 1_000;
+	pub const MaxValidatorsCount: u32 = 4_000;
+	pub const MaxUnlockingChunks: u32 = 32;
+	pub const MaxKeysEncodingSize: u32 = 1_000;
 }
 
 impl frame_election_provider_support::onchain::Config for Runtime {
 	type Accuracy = runtime_common::elections::OnOnChainAccuracy;
 	type DataProvider = Staking;
+	type MaxNominations = MaxNominations;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 impl pallet_staking::Config for Runtime {
-	const MAX_NOMINATIONS: u32 = 16;
 	type Currency = Balances;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = frame_support::traits::U128CurrencyToVote;
@@ -335,7 +348,16 @@ impl pallet_staking::Config for Runtime {
 	type SlashCancelOrigin = frame_system::EnsureNever<()>;
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
-	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
+	type MaxRewardableIndividualExposures = MaxRewardableIndividualExposures;
+	type MaxIndividualExposures = MaxIndividualExposures;
+	type MaxNominations = MaxNominations;
+	type MaxUnappliedSlashes = MaxUnappliedSlashes;
+	type MaxInvulnerablesCount = MaxInvulnerablesCount;
+	type MaxHistoryDepth = MaxHistoryDepth;
+	type MaxReportersCount = MaxReportersCount;
+	type MaxPriorSlashingSpans = MaxPriorSlashingSpans;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxUnlockingChunks = MaxUnlockingChunks;
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	type NextNewSession = Session;
 	type ElectionProvider =
@@ -365,7 +387,8 @@ impl pallet_grandpa::Config for Runtime {
 	type HandleEquivocation = ();
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl<LocalCall> frame_system::offchain::CreateSignedTransaction<LocalCall> for Runtime
@@ -416,10 +439,11 @@ impl pallet_offences::Config for Runtime {
 	type Event = Event;
 	type IdentificationTuple = pallet_session::historical::IdentificationTuple<Self>;
 	type OnOffenceHandler = Staking;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_authority_discovery::Config for Runtime {
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
 }
 
 parameter_types! {
diff --git a/runtime/westend/src/lib.rs b/runtime/westend/src/lib.rs
index 646a4a18f351..627a92d06dfb 100644
--- a/runtime/westend/src/lib.rs
+++ b/runtime/westend/src/lib.rs
@@ -228,7 +228,8 @@ impl pallet_babe::Config for Runtime {
 
 	type WeightInfo = ();
 
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 parameter_types! {
@@ -323,10 +324,12 @@ impl pallet_session::Config for Runtime {
 	type SessionHandler = <SessionKeys as OpaqueKeys>::KeyTypeIdProviders;
 	type Keys = SessionKeys;
 	type WeightInfo = weights::pallet_session::WeightInfo<Runtime>;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxKeysEncodingSize = MaxKeysEncodingSize;
 }
 
 impl pallet_session::historical::Config for Runtime {
-	type FullIdentification = pallet_staking::Exposure<AccountId, Balance>;
+	type FullIdentification = pallet_staking::Exposure<AccountId, Balance, MaxIndividualExposures>;
 	type FullIdentificationOf = pallet_staking::ExposureOf<Runtime>;
 }
 
@@ -392,6 +395,7 @@ impl pallet_election_provider_multi_phase::Config for Runtime {
 	type ForceOrigin = EnsureRoot<AccountId>;
 	type WeightInfo = weights::pallet_election_provider_multi_phase::WeightInfo<Self>;
 	type VoterSnapshotPerBlock = VoterSnapshotPerBlock;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 parameter_types! {
@@ -424,18 +428,28 @@ parameter_types! {
 	// 27 eras in which slashes can be cancelled (slightly less than 7 days).
 	pub const SlashDeferDuration: pallet_staking::EraIndex = 27;
 	pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
-	pub const MaxNominatorRewardedPerValidator: u32 = 64;
+	pub const MaxRewardableIndividualExposures: u32 = 64;
+	pub const MaxIndividualExposures: u32 = 1_000;
+	pub const MaxNominations: u32 = <NposCompactSolution16 as sp_npos_elections::NposSolution>::LIMIT as u32;
+	pub const MaxUnappliedSlashes: u32 = 1_000;
+	pub const MaxInvulnerablesCount: u32 = 10;
+	pub const MaxHistoryDepth: u32 = 10_000;
+	pub const MaxReportersCount: u32 = 1_000;
+	pub const MaxPriorSlashingSpans: u32 = 1_000;
+	pub const MaxValidatorsCount: u32 = 4_000;
+	pub const MaxKeysEncodingSize: u32 = 1_000;
+	pub const MaxUnlockingChunks: u32 = 32;
 	pub const OffendingValidatorsThreshold: Perbill = Perbill::from_percent(17);
 }
 
 impl frame_election_provider_support::onchain::Config for Runtime {
 	type Accuracy = runtime_common::elections::OnOnChainAccuracy;
 	type DataProvider = Staking;
+	type MaxNominations = MaxNominations;
+	type MaxTargets = MaxValidatorsCount;
 }
 
 impl pallet_staking::Config for Runtime {
-	const MAX_NOMINATIONS: u32 =
-		<NposCompactSolution16 as sp_npos_elections::NposSolution>::LIMIT as u32;
 	type Currency = Balances;
 	type UnixTime = Timestamp;
 	type CurrencyToVote = CurrencyToVote;
@@ -450,7 +464,16 @@ impl pallet_staking::Config for Runtime {
 	type SlashCancelOrigin = EnsureRoot<AccountId>;
 	type SessionInterface = Self;
 	type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
-	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
+	type MaxRewardableIndividualExposures = MaxRewardableIndividualExposures;
+	type MaxIndividualExposures = MaxIndividualExposures;
+	type MaxNominations = MaxNominations;
+	type MaxUnappliedSlashes = MaxUnappliedSlashes;
+	type MaxInvulnerablesCount = MaxInvulnerablesCount;
+	type MaxHistoryDepth = MaxHistoryDepth;
+	type MaxReportersCount = MaxReportersCount;
+	type MaxPriorSlashingSpans = MaxPriorSlashingSpans;
+	type MaxValidatorsCount = MaxValidatorsCount;
+	type MaxUnlockingChunks = MaxUnlockingChunks;
 	type OffendingValidatorsThreshold = OffendingValidatorsThreshold;
 	type NextNewSession = Session;
 	type ElectionProvider = ElectionProviderMultiPhase;
@@ -470,23 +493,22 @@ parameter_types! {
 	// One cent: $10,000 / MB
 	pub const PreimageByteDeposit: Balance = 10 * MILLICENTS;
 	pub const InstantAllowed: bool = true;
-	pub const MaxAuthorities: u32 = 100_000;
 }
 
 impl pallet_offences::Config for Runtime {
 	type Event = Event;
 	type IdentificationTuple = pallet_session::historical::IdentificationTuple<Self>;
 	type OnOffenceHandler = Staking;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_authority_discovery::Config for Runtime {
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
 }
 
 parameter_types! {
 	pub const NposSolutionPriority: TransactionPriority = TransactionPriority::max_value() / 2;
 	pub const ImOnlineUnsignedPriority: TransactionPriority = TransactionPriority::max_value();
-	pub const MaxKeys: u32 = 10_000;
 	pub const MaxPeerInHeartbeats: u32 = 10_000;
 	pub const MaxPeerDataEncodingSize: u32 = 1_000;
 }
@@ -499,9 +521,10 @@ impl pallet_im_online::Config for Runtime {
 	type ReportUnresponsiveness = Offences;
 	type UnsignedPriority = ImOnlineUnsignedPriority;
 	type WeightInfo = weights::pallet_im_online::WeightInfo<Runtime>;
-	type MaxKeys = MaxKeys;
+	type MaxKeys = MaxValidatorsCount;
 	type MaxPeerInHeartbeats = MaxPeerInHeartbeats;
 	type MaxPeerDataEncodingSize = MaxPeerDataEncodingSize;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 impl pallet_grandpa::Config for Runtime {
@@ -525,7 +548,8 @@ impl pallet_grandpa::Config for Runtime {
 	>;
 
 	type WeightInfo = ();
-	type MaxAuthorities = MaxAuthorities;
+	type MaxAuthorities = MaxValidatorsCount;
+	type MaxReportersCount = MaxReportersCount;
 }
 
 /// Submits a transaction with the node's public and signature type. Adheres to the signed extension
diff --git a/runtime/westend/src/weights/pallet_staking.rs b/runtime/westend/src/weights/pallet_staking.rs
index 7392df46e267..e5485030f42e 100644
--- a/runtime/westend/src/weights/pallet_staking.rs
+++ b/runtime/westend/src/weights/pallet_staking.rs
@@ -111,7 +111,6 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking MinValidatorBond (r:1 w:0)
 	// Storage: Staking Validators (r:1 w:1)
-	// Storage: Staking MaxValidatorsCount (r:1 w:0)
 	// Storage: Staking Nominators (r:1 w:1)
 	// Storage: Staking CounterForNominators (r:1 w:1)
 	// Storage: BagsList ListNodes (r:2 w:2)
@@ -120,7 +119,7 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 	// Storage: Staking CounterForValidators (r:1 w:1)
 	fn validate() -> Weight {
 		(65_171_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(11 as Weight))
+			.saturating_add(T::DbWeight::get().reads(10 as Weight))
 			.saturating_add(T::DbWeight::get().writes(8 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
@@ -386,13 +385,12 @@ impl<T: frame_system::Config> pallet_staking::WeightInfo for WeightInfo<T> {
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
 	// Storage: Staking MinValidatorBond (r:0 w:1)
-	// Storage: Staking MaxValidatorsCount (r:0 w:1)
 	// Storage: Staking ChillThreshold (r:0 w:1)
 	// Storage: Staking MaxNominatorsCount (r:0 w:1)
 	// Storage: Staking MinNominatorBond (r:0 w:1)
 	fn set_staking_limits() -> Weight {
 		(5_641_000 as Weight)
-			.saturating_add(T::DbWeight::get().writes(5 as Weight))
+			.saturating_add(T::DbWeight::get().writes(4 as Weight))
 	}
 	// Storage: Staking Ledger (r:1 w:0)
 	// Storage: Staking ChillThreshold (r:1 w:0)