diff --git a/.circleci/config.yml b/.circleci/config.yml
index 7d187778889f..5e7cc4a22d24 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -195,6 +195,11 @@ jobs:
           command: |
             cd scripts
             yarn get-template --check
+      - run:
+          name: Type check
+          command: |
+            cd scripts
+            yarn check
       - run:
           name: Run tests
           command: |
diff --git a/scripts/event-log-collector.ts b/scripts/event-log-collector.ts
index 160120428553..f3ad10700887 100644
--- a/scripts/event-log-collector.ts
+++ b/scripts/event-log-collector.ts
@@ -12,7 +12,7 @@ server.post('/event-log', (req, res) => {
   res.end('OK');
 });
 
-server.get('/event-log', (req, res) => {
+server.get('/event-log', (_req, res) => {
   console.log(`Sending ${events.length} events`);
   res.json(events);
 });
diff --git a/scripts/package.json b/scripts/package.json
index 6b7d18750111..eff165cd7f76 100644
--- a/scripts/package.json
+++ b/scripts/package.json
@@ -3,6 +3,7 @@
   "version": "7.0.0-alpha.16",
   "private": true,
   "scripts": {
+    "check": "./prepare/check-scripts.ts",
     "docs:prettier:check": "cd ../docs && prettier --check ./snippets",
     "docs:prettier:write": "cd ../docs && prettier --write ./snippets",
     "get-report-message": "ts-node --swc ./get-report-message.ts",
@@ -175,6 +176,7 @@
     "slash": "^3.0.0",
     "sort-package-json": "^2.0.0",
     "tempy": "^1.0.0",
+    "tiny-invariant": "^1.3.1",
     "trash": "^7.0.0",
     "ts-dedent": "^2.0.0",
     "ts-node": "^10.9.1",
diff --git a/scripts/prepare/check-scripts.ts b/scripts/prepare/check-scripts.ts
new file mode 100755
index 000000000000..86418acd93ba
--- /dev/null
+++ b/scripts/prepare/check-scripts.ts
@@ -0,0 +1,75 @@
+#!/usr/bin/env ./node_modules/.bin/ts-node-script
+
+import { join } from 'path';
+import * as ts from 'typescript';
+
+const run = async ({ cwd }: { cwd: string }) => {
+  const { options, fileNames } = getTSFilesAndConfig('tsconfig.json');
+  const { program, host } = getTSProgramAndHost(fileNames, options);
+
+  const tsDiagnostics = getTSDiagnostics(program, cwd, host);
+  if (tsDiagnostics.length > 0) {
+    console.log(tsDiagnostics);
+    process.exit(1);
+  } else {
+    console.log('no type errors');
+  }
+
+  // TODO, add more package checks here, like:
+  // - check for missing dependencies/peerDependencies
+  // - check for unused exports
+
+  console.log('done');
+};
+
+run({ cwd: process.cwd() }).catch((err: unknown) => {
+  // We can't let the stack try to print, it crashes in a way that sets the exit code to 0.
+  // Seems to have something to do with running JSON.parse() on binary / base64 encoded sourcemaps
+  // in @cspotcode/source-map-support
+  if (err instanceof Error) {
+    console.error(err.message);
+  }
+  process.exit(1);
+});
+
+function getTSDiagnostics(program: ts.Program, cwd: string, host: ts.CompilerHost): any {
+  return ts.formatDiagnosticsWithColorAndContext(
+    ts.getPreEmitDiagnostics(program).filter((d) => d.file.fileName.startsWith(cwd)),
+    host
+  );
+}
+
+function getTSProgramAndHost(fileNames: string[], options: ts.CompilerOptions) {
+  const program = ts.createProgram({
+    rootNames: fileNames,
+    options: {
+      module: ts.ModuleKind.CommonJS,
+      ...options,
+      declaration: false,
+      noEmit: true,
+    },
+  });
+
+  const host = ts.createCompilerHost(program.getCompilerOptions());
+  return { program, host };
+}
+
+function getTSFilesAndConfig(tsconfigPath: string) {
+  const content = ts.readJsonConfigFile(tsconfigPath, ts.sys.readFile);
+  return ts.parseJsonSourceFileConfigFileContent(
+    content,
+    {
+      useCaseSensitiveFileNames: true,
+      readDirectory: ts.sys.readDirectory,
+      fileExists: ts.sys.fileExists,
+      readFile: ts.sys.readFile,
+    },
+    process.cwd(),
+    {
+      noEmit: true,
+      outDir: join(process.cwd(), 'types'),
+      target: ts.ScriptTarget.ES2022,
+      declaration: false,
+    }
+  );
+}
diff --git a/scripts/prepare/esm-bundle.ts b/scripts/prepare/esm-bundle.ts
index 33a7c8314bae..08e039ad6dd2 100755
--- a/scripts/prepare/esm-bundle.ts
+++ b/scripts/prepare/esm-bundle.ts
@@ -13,7 +13,8 @@ import { exec } from '../utils/exec';
 /* TYPES */
 
 type BundlerConfig = {
-  entries: string[];
+  browserEntries: string[];
+  nodeEntries: string[];
   externals: string[];
   pre: string;
   post: string;
diff --git a/scripts/release/pick-patches.ts b/scripts/release/pick-patches.ts
index bbd90fb415e5..82f1fe2b4a1a 100644
--- a/scripts/release/pick-patches.ts
+++ b/scripts/release/pick-patches.ts
@@ -6,6 +6,7 @@ import ora from 'ora';
 import { setOutput } from '@actions/core';
 import { git } from './utils/git-client';
 import { getUnpickedPRs } from './utils/github-client';
+import invariant from 'tiny-invariant';
 
 program.name('pick-patches').description('Cherry pick patch PRs back to main');
 
@@ -57,6 +58,7 @@ export const run = async (_: unknown) => {
       await git.raw(['cherry-pick', '-m', '1', '--keep-redundant-commits', '-x', pr.mergeCommit]);
       prSpinner.succeed(`Picked: ${formatPR(pr)}`);
     } catch (pickError) {
+      invariant(pickError instanceof Error);
       prSpinner.fail(`Failed to automatically pick: ${formatPR(pr)}`);
       logger.error(pickError.message);
       const abort = ora(`Aborting cherry pick for merge commit: ${pr.mergeCommit}`).start();
@@ -64,8 +66,9 @@ export const run = async (_: unknown) => {
         await git.raw(['cherry-pick', '--abort']);
         abort.stop();
       } catch (abortError) {
+        invariant(abortError instanceof Error);
         abort.warn(`Failed to abort cherry pick (${pr.mergeCommit})`);
-        logger.error(pickError.message);
+        logger.error(abortError.message);
       }
       failedCherryPicks.push(pr.mergeCommit);
       prSpinner.info(
diff --git a/scripts/release/utils/get-github-info.ts b/scripts/release/utils/get-github-info.ts
index 65508bcc05ae..6bd7126aec04 100644
--- a/scripts/release/utils/get-github-info.ts
+++ b/scripts/release/utils/get-github-info.ts
@@ -97,7 +97,7 @@ function makeQuery(repos: ReposWithCommitsAndPRsToFetch) {
 // getReleaseLine will be called a large number of times but it'll be called at the same time
 // so instead of doing a bunch of network requests, we can do a single one.
 const GHDataLoader = new DataLoader(
-  async (requests: RequestData[]) => {
+  async (requests: readonly RequestData[]) => {
     if (!process.env.GH_TOKEN) {
       throw new Error(
         'Please create a GitHub personal access token at https://github.com/settings/tokens/new with `read:user` and `repo:status` permissions and add it as the GH_TOKEN environment variable'
diff --git a/scripts/release/version.ts b/scripts/release/version.ts
index 1636b248b454..3b34d288a8c7 100644
--- a/scripts/release/version.ts
+++ b/scripts/release/version.ts
@@ -141,12 +141,10 @@ const bumpVersionSources = async (currentVersion: string, nextVersion: string) =
 
 const bumpAllPackageJsons = async ({
   packages,
-  currentVersion,
   nextVersion,
   verbose,
 }: {
   packages: Workspace[];
-  currentVersion: string;
   nextVersion: string;
   verbose?: boolean;
 }) => {
@@ -279,7 +277,7 @@ export const run = async (options: unknown) => {
 
     await bumpCodeVersion(nextVersion);
     await bumpVersionSources(currentVersion, nextVersion);
-    await bumpAllPackageJsons({ packages, currentVersion, nextVersion, verbose });
+    await bumpAllPackageJsons({ packages, nextVersion, verbose });
 
     console.log(`⬆️ Updating lock file with ${chalk.blue('yarn install --mode=update-lockfile')}`);
     await execaCommand(`yarn install --mode=update-lockfile`, {
diff --git a/scripts/sandbox/utils/git.ts b/scripts/sandbox/utils/git.ts
index e4261083c9a5..84fe02f25cdb 100644
--- a/scripts/sandbox/utils/git.ts
+++ b/scripts/sandbox/utils/git.ts
@@ -1,4 +1,6 @@
 import fetch from 'node-fetch';
+import invariant from 'tiny-invariant';
+
 import { execaCommand } from '../../utils/exec';
 // eslint-disable-next-line import/no-cycle
 import { logger } from '../publish';
@@ -27,9 +29,9 @@ const getTheLastCommitHashThatUpdatedTheSandboxRepo = async (branch: string) =>
         `Could not find the last commit hash in the following commit message: "${latestCommitMessage}".\nDid someone manually push to the sandboxes repo?`
       );
     }
-
     return lastCommitHash;
   } catch (error) {
+    invariant(error instanceof Error);
     if (!error.message.includes('Did someone manually push to the sandboxes repo')) {
       logger.error(
         `⚠️  Error getting latest commit message of ${owner}/${repo} on branch ${branch}: ${error.message}`
@@ -84,6 +86,7 @@ export async function commitAllToGit({ cwd, branch }: { cwd: string; branch: str
       ].join('\n');
       gitCommitCommand = `git commit -m "${commitTitle}" -m "${commitBody}"`;
     } catch (err) {
+      invariant(err instanceof Error);
       logger.log(
         `⚠️  Falling back to a simpler commit message because of an error while trying to get the previous commit hash: ${err.message}`
       );
@@ -95,6 +98,7 @@ export async function commitAllToGit({ cwd, branch }: { cwd: string; branch: str
       cwd,
     });
   } catch (e) {
+    invariant(e instanceof Error);
     if (e.message.includes('nothing to commit')) {
       logger.log(
         `🤷 Git found no changes between previous versions so there is nothing to commit. Skipping publish!`
diff --git a/scripts/sandbox/utils/template.ts b/scripts/sandbox/utils/template.ts
index 4cc3723827f0..10fdef474eb1 100644
--- a/scripts/sandbox/utils/template.ts
+++ b/scripts/sandbox/utils/template.ts
@@ -33,20 +33,17 @@ export async function getTemplatesData(branch: string) {
     >
   >;
 
-  const templatesData = Object.keys(sandboxTemplates).reduce<TemplatesData>(
-    (acc, curr: keyof typeof sandboxTemplates) => {
-      const [dirName, templateName] = curr.split('/');
-      const groupName =
-        dirName === 'cra' ? 'CRA' : dirName.slice(0, 1).toUpperCase() + dirName.slice(1);
-      const generatorData = sandboxTemplates[curr];
-      acc[groupName] = acc[groupName] || {};
-      acc[groupName][templateName] = {
-        ...generatorData,
-        stackblitzUrl: getStackblitzUrl(curr, branch),
-      };
-      return acc;
-    },
-    {}
-  );
+  const templatesData = Object.keys(sandboxTemplates).reduce<TemplatesData>((acc, curr) => {
+    const [dirName, templateName] = curr.split('/');
+    const groupName =
+      dirName === 'cra' ? 'CRA' : dirName.slice(0, 1).toUpperCase() + dirName.slice(1);
+    const generatorData = sandboxTemplates[curr as keyof typeof sandboxTemplates];
+    acc[groupName] = acc[groupName] || {};
+    acc[groupName][templateName] = {
+      ...generatorData,
+      stackblitzUrl: getStackblitzUrl(curr, branch),
+    };
+    return acc;
+  }, {});
   return templatesData;
 }
diff --git a/scripts/task.ts b/scripts/task.ts
index 67a70ae30a86..9e18d1f618c2 100644
--- a/scripts/task.ts
+++ b/scripts/task.ts
@@ -35,6 +35,7 @@ import {
 } from '../code/lib/cli/src/sandbox-templates';
 
 import { version } from '../code/package.json';
+import invariant from 'tiny-invariant';
 
 const sandboxDir = process.env.SANDBOX_ROOT || SANDBOX_DIRECTORY;
 
@@ -73,7 +74,7 @@ export type Task = {
   /**
    * Is this task already "ready", and potentially not required?
    */
-  ready: (details: TemplateDetails, options: PassedOptionValues) => MaybePromise<boolean>;
+  ready: (details: TemplateDetails, options?: PassedOptionValues) => MaybePromise<boolean>;
   /**
    * Run the task
    */
@@ -320,6 +321,7 @@ async function runTask(task: Task, details: TemplateDetails, optionValues: Passe
 
     return controller;
   } catch (err) {
+    invariant(err instanceof Error);
     const hasJunitFile = await pathExists(junitFilename);
     // If there's a non-test related error (junit report has not been reported already), we report the general failure in a junit report
     if (junitFilename && !hasJunitFile) {
@@ -466,6 +468,7 @@ async function run() {
         });
         if (controller) controllers.push(controller);
       } catch (err) {
+        invariant(err instanceof Error);
         logger.error(`Error running task ${getTaskKey(task)}:`);
         // If it is the last task, we don't need to log the full trace
         if (task === finalTask) {
diff --git a/scripts/tasks/sandbox-parts.ts b/scripts/tasks/sandbox-parts.ts
index fadbdf41c901..f0aaa39d825d 100644
--- a/scripts/tasks/sandbox-parts.ts
+++ b/scripts/tasks/sandbox-parts.ts
@@ -390,8 +390,7 @@ export const addStories: Task['run'] = async (
   // Ensure that we match the right stories in the stories directory
   updateStoriesField(
     mainConfig,
-    (await detectLanguage(packageManager)) === SupportedLanguage.JAVASCRIPT,
-    disableDocs
+    (await detectLanguage(packageManager)) === SupportedLanguage.JAVASCRIPT
   );
 
   const isCoreRenderer =
diff --git a/scripts/ts-to-ts49.ts b/scripts/ts-to-ts49.ts
index a73eaabbd2be..869d71bfb9a2 100644
--- a/scripts/ts-to-ts49.ts
+++ b/scripts/ts-to-ts49.ts
@@ -7,6 +7,7 @@ import * as recast from 'recast';
 import type Babel from '@babel/core';
 import type { File } from '@babel/types';
 import * as t from '@babel/types';
+import invariant from 'tiny-invariant';
 
 const files = glob.sync('**/*.ts.mdx', {
   absolute: true,
@@ -74,6 +75,7 @@ for (const [, file] of files.entries()) {
       console.log('changed', file);
     }
   } catch (e) {
+    invariant(e instanceof Error);
     console.error(e.message);
   }
 }
diff --git a/scripts/tsconfig.json b/scripts/tsconfig.json
index 591055d2ab92..c82e14a95108 100644
--- a/scripts/tsconfig.json
+++ b/scripts/tsconfig.json
@@ -8,14 +8,14 @@
     "moduleResolution": "Node",
     "target": "ES2020",
     "module": "CommonJS",
-    "skipLibCheck": false,
+    "skipLibCheck": true,
     "allowSyntheticDefaultImports": true,
     "esModuleInterop": true,
     "isolatedModules": true,
     "strictBindCallApply": true,
     "lib": ["dom", "esnext"],
     "types": ["node", "jest"],
-    "strict": false,
+    "strict": true,
     "strictNullChecks": false,
     "forceConsistentCasingInFileNames": true,
     "noUnusedLocals": true,
diff --git a/scripts/utils/exec.ts b/scripts/utils/exec.ts
index 6280f65ff9cf..74a886189420 100644
--- a/scripts/utils/exec.ts
+++ b/scripts/utils/exec.ts
@@ -67,7 +67,7 @@ export const exec = async (
       }
     }
   } catch (err) {
-    if (!err.killed) {
+    if (!(typeof err === 'object' && 'killed' in err && err.killed)) {
       logger.error(chalk.red(`An error occurred while executing: \`${command}\``));
       logger.log(`${errorMessage}\n`);
     }
diff --git a/scripts/utils/options.test.ts b/scripts/utils/options.test.ts
index ccbc6a058ec3..c183db207f2c 100644
--- a/scripts/utils/options.test.ts
+++ b/scripts/utils/options.test.ts
@@ -1,7 +1,6 @@
 import { describe, expect, it } from '@jest/globals';
 import { createCommand } from 'commander';
 
-import type { MaybeOptionValues, OptionValues } from './options';
 import { areOptionsSatisfied, createOptions, getCommand, getOptions } from './options';
 
 const allOptions = createOptions({
@@ -35,17 +34,6 @@ const allOptions = createOptions({
   },
 });
 
-// TS "tests"
-// deepscan-disable-next-line
-function test(mv: MaybeOptionValues<typeof allOptions>, v: OptionValues<typeof allOptions>) {
-  console.log(mv.first, mv.second, mv.third, mv.fourth, mv.fifth, mv.sixth);
-  // @ts-expect-error as it's not allowed
-  console.log(mv.seventh);
-  console.log(v.first, v.second, v.third, v.fourth, v.fifth, v.sixth);
-  // @ts-expect-error as it's not allowed
-  console.log(v.seventh);
-}
-
 describe('getOptions', () => {
   it('deals with boolean options', () => {
     expect(getOptions(createCommand(), allOptions, ['command', 'name', '--first'])).toMatchObject({
@@ -71,7 +59,6 @@ describe('getOptions', () => {
   });
 
   it('deals with string options', () => {
-    const r = getOptions(createCommand(), allOptions, ['command', 'name', '--third', 'one']);
     expect(
       getOptions(createCommand(), allOptions, ['command', 'name', '--third', 'one'])
     ).toMatchObject({
diff --git a/scripts/yarn.lock b/scripts/yarn.lock
index 6fe301173b5d..be6fe9587929 100644
--- a/scripts/yarn.lock
+++ b/scripts/yarn.lock
@@ -3033,6 +3033,7 @@ __metadata:
     slash: ^3.0.0
     sort-package-json: ^2.0.0
     tempy: ^1.0.0
+    tiny-invariant: ^1.3.1
     trash: ^7.0.0
     ts-dedent: ^2.0.0
     ts-loader: ^9.4.2
@@ -15618,6 +15619,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"tiny-invariant@npm:^1.3.1":
+  version: 1.3.1
+  resolution: "tiny-invariant@npm:1.3.1"
+  checksum: 5b87c1d52847d9452b60d0dcb77011b459044e0361ca8253bfe7b43d6288106e12af926adb709a6fc28900e3864349b91dad9a4ac93c39aa15f360b26c2ff4db
+  languageName: node
+  linkType: hard
+
 "tmp@npm:~0.2.1":
   version: 0.2.1
   resolution: "tmp@npm:0.2.1"