diff --git a/apps/meteor/app/api/server/v1/settings.ts b/apps/meteor/app/api/server/v1/settings.ts
index 011988f5ba2e6..bccfc8d91fc7b 100644
--- a/apps/meteor/app/api/server/v1/settings.ts
+++ b/apps/meteor/app/api/server/v1/settings.ts
@@ -106,7 +106,7 @@ API.v1.addRoute(
 	{ authRequired: true, twoFactorRequired: true },
 	{
 		async post() {
-			if (!this.bodyParams.name || !this.bodyParams.name.trim()) {
+			if (!this.bodyParams.name?.trim()) {
 				throw new Meteor.Error('error-name-param-not-provided', 'The parameter "name" is required');
 			}
 
diff --git a/apps/meteor/app/apps/server/bridges/listeners.js b/apps/meteor/app/apps/server/bridges/listeners.js
index b1ee4fd145211..ab2632c912b0d 100644
--- a/apps/meteor/app/apps/server/bridges/listeners.js
+++ b/apps/meteor/app/apps/server/bridges/listeners.js
@@ -7,6 +7,7 @@ export class AppListenerBridge {
 	}
 
 	async handleEvent(event, ...payload) {
+		// eslint-disable-next-line complexity
 		const method = (() => {
 			switch (event) {
 				case AppInterface.IPreMessageSentPrevent:
diff --git a/apps/meteor/app/authorization/lib/AuthorizationUtils.ts b/apps/meteor/app/authorization/lib/AuthorizationUtils.ts
index 41c96bd6fd3ae..6ad5cab047209 100644
--- a/apps/meteor/app/authorization/lib/AuthorizationUtils.ts
+++ b/apps/meteor/app/authorization/lib/AuthorizationUtils.ts
@@ -31,7 +31,7 @@ export const AuthorizationUtils = class {
 		}
 
 		const rules = restrictedRolePermissions.get(roleId);
-		if (!rules || !rules.size) {
+		if (!rules?.size) {
 			return false;
 		}
 
diff --git a/apps/meteor/app/cors/server/cors.ts b/apps/meteor/app/cors/server/cors.ts
index b4936d1456bc5..3090530140168 100644
--- a/apps/meteor/app/cors/server/cors.ts
+++ b/apps/meteor/app/cors/server/cors.ts
@@ -7,7 +7,6 @@ import { Logger } from '@rocket.chat/logger';
 import { Meteor } from 'meteor/meteor';
 import type { StaticFiles } from 'meteor/webapp';
 import { WebApp, WebAppInternals } from 'meteor/webapp';
-import _ from 'underscore';
 
 import { settings } from '../../settings/server';
 
@@ -174,7 +173,7 @@ WebApp.httpServer.addListener('request', (req, res, ...args) => {
 
 	const isLocal =
 		localhostRegexp.test(remoteAddress) &&
-		(!req.headers['x-forwarded-for'] || _.all((req.headers['x-forwarded-for'] as string).split(','), localhostTest));
+		(!req.headers['x-forwarded-for'] || (req.headers['x-forwarded-for'] as string).split(',').every(localhostTest));
 	// @ts-expect-error - `pair` is valid, but doesnt exists on types
 	const isSsl = req.connection.pair || (req.headers['x-forwarded-proto'] && req.headers['x-forwarded-proto'].indexOf('https') !== -1);
 
diff --git a/apps/meteor/app/lib/server/functions/getAvatarSuggestionForUser.ts b/apps/meteor/app/lib/server/functions/getAvatarSuggestionForUser.ts
index a54704cf8862b..2560d2f08b7de 100644
--- a/apps/meteor/app/lib/server/functions/getAvatarSuggestionForUser.ts
+++ b/apps/meteor/app/lib/server/functions/getAvatarSuggestionForUser.ts
@@ -167,7 +167,7 @@ export async function getAvatarSuggestionForUser(
 				let blob = `data:${response.headers.get('content-type')};base64,`;
 				blob += Buffer.from(await response.arrayBuffer()).toString('base64');
 				newAvatar.blob = blob;
-				newAvatar.contentType = response.headers.get('content-type')!;
+				newAvatar.contentType = response.headers.get('content-type') as string;
 				validAvatars[avatar.service] = newAvatar;
 			}
 		} catch (error) {
diff --git a/packages/gazzodown/src/elements/Timestamp/ErrorBoundary.tsx b/packages/gazzodown/src/elements/Timestamp/ErrorBoundary.tsx
index 55ef57ad1deef..453853275f8ad 100644
--- a/packages/gazzodown/src/elements/Timestamp/ErrorBoundary.tsx
+++ b/packages/gazzodown/src/elements/Timestamp/ErrorBoundary.tsx
@@ -1,4 +1,4 @@
-import { Component } from 'react';
+import React, { Component, ReactNode } from 'react';
 
 export class ErrorBoundary extends Component<{ fallback: React.ReactNode }, { hasError: boolean }> {
 	constructor(props: { fallback: React.ReactNode }) {
@@ -6,11 +6,11 @@ export class ErrorBoundary extends Component<{ fallback: React.ReactNode }, { ha
 		this.state = { hasError: false };
 	}
 
-	static getDerivedStateFromError() {
+	static getDerivedStateFromError(): { hasError: boolean } {
 		return { hasError: true };
 	}
 
-	render() {
+	render(): ReactNode {
 		if (this.state.hasError) {
 			// You can render any custom fallback UI
 			return this.props.fallback;
diff --git a/packages/livechat/src/components/Composer/index.tsx b/packages/livechat/src/components/Composer/index.tsx
index 2562a40debdc1..1f1ce3b7369d9 100644
--- a/packages/livechat/src/components/Composer/index.tsx
+++ b/packages/livechat/src/components/Composer/index.tsx
@@ -6,9 +6,9 @@ import { createClassName } from '../../helpers/createClassName';
 import { parse } from '../../helpers/parse';
 import styles from './styles.scss';
 
-const findLastTextNode = (node: Node): Text | null => {
+const findLastTextNode = (node: Node): Node | null => {
 	if (node.nodeType === Node.TEXT_NODE) {
-		return node as Text;
+		return node;
 	}
 	const children = node.childNodes;
 	for (let i = children.length - 1; i >= 0; i--) {
@@ -26,7 +26,7 @@ const replaceCaret = (el: Element) => {
 	const target = findLastTextNode(el);
 	// do not move caret if element was not focused
 	const isTargetFocused = document.activeElement === el;
-	if (target !== null && target.nodeValue !== null && isTargetFocused) {
+	if (!!target?.nodeValue && isTargetFocused) {
 		const range = document.createRange();
 		const sel = window.getSelection();
 		range.setStart(target, target.nodeValue.length);
@@ -241,7 +241,7 @@ export class Composer extends Component<ComposerProps, ComposerState> {
 		}
 
 		if (typeof win.getSelection !== 'undefined' && (win.getSelection()?.rangeCount ?? 0) > 0) {
-			const range = win.getSelection()!.getRangeAt(0);
+			const range = win.getSelection()?.getRangeAt(0) as Range;
 			const preCaretRange = range.cloneRange();
 			preCaretRange.selectNodeContents(element);
 			preCaretRange.setEnd(range.endContainer, range.endOffset);
@@ -249,10 +249,10 @@ export class Composer extends Component<ComposerProps, ComposerState> {
 		}
 
 		if (doc.selection && doc.selection.type !== 'Control') {
-			const textRange = doc.selection.createRange!();
+			const textRange = doc.selection.createRange?.();
 			const preCaretTextRange = doc.body.createTextRange?.();
 			preCaretTextRange?.moveToElementText?.(element);
-			preCaretTextRange?.setEndPoint?.('EndToEnd', textRange);
+			preCaretTextRange?.setEndPoint?.('EndToEnd', textRange as Range);
 			return preCaretTextRange?.text?.length ?? 0;
 		}