TypeScript

Lessons

1. 1

   Why TypeScript Exists

   Free

   Explain the problems TS solves, the tradeoffs, and why it's the 2026 default.

   Intermediate·30 min
2. 2

   TypeScript Setup: tsconfig + strict mode

   Configure tsconfig.json correctly; understand each strict-mode flag.

   Intermediate·45 min
3. 3

   Type System Fundamentals

   Use primitive, object, array, tuple, enum, literal, union, intersection types.

   Intermediate·50 min
4. 4

   Functions in TypeScript

   Type function signatures, optional + default + overloaded parameters.

   Intermediate·40 min
5. 5

   Interfaces vs Type Aliases

   Pick interface vs type alias; understand declaration merging.

   Intermediate·35 min
6. 6

   Generics

   Write generic functions, interfaces, constraints, and default type parameters.

   Advanced·55 min
7. 7

   Advanced Types

   Use mapped, conditional, template literal types and the built-in utility types.

   Advanced·55 min
8. 8

   TypeScript with React

   Type props, hooks, events, context, and refs in React.

   Intermediate·45 min
9. 9

   TypeScript with Node.js + Express/Fastify

   Type request / response handlers + middleware in Express or Fastify.

   Intermediate·45 min
10. 10

    Declaration Files (.d.ts)

    Read existing .d.ts files; write your own for untyped libraries.

    Advanced·35 min
11. 11

    Decorators, Metadata, and NestJS

    Understand how decorators + metadata work and read/write decorator-driven NestJS and TypeORM code.

    Advanced·45 min
12. 12

    Migrating JavaScript to TypeScript

    Migrate a JS codebase to TS incrementally with allowJs and a strictness ratchet, without halting feature work.

    Intermediate·40 min
13. 13

    Passion Project: Type-First TS Library

    Publish a fully type-inferred TS library where generics and conditional types give consumers zero-annotation autocomplete.

    Advanced·180 min
14. 14

    TypeScript Job Readiness

    Translate TS skills into resume bullets + interview answers.

    Beginner·30 min