TypeScript From Zero

A blog series

TypeScript From Zero to Confident

TypeScript from the first project to real-world configuration: basic types and narrowing, objects and classes, functions and generics, utility and conditional types, modules and tsconfig, React and runtime validation with Zod, and migrating to strict mode. Every compiler error shown was reproduced.

Started 
2026
Lessons 
8
Reading 
~3 h

Contents

Every lesson has the same steps: what it is, how it works, a real example, common mistakes, then interview questions with answers you can say out loud.

  1. Lesson 00Why TypeScript, and Your First ProjectWhat TypeScript is and is not, why types are erased at runtime, setting up a project, a tsconfig explained line by line, and reading your first compiler errors.20 min
  2. Lesson 01Basic Types, Inference and NarrowingPrimitives, unions, literal types, any versus unknown versus never, inference, narrowing and discriminated unions.22 min
  3. Lesson 02Objects, Interfaces, Type Aliases and ClassesObject types, interface versus type, structural typing, excess-property checks, classes, enums versus unions, as const and satisfies.22 min
  4. Lesson 03Functions and GenericsFunction types, overloads, this parameters, generics and constraints, a typed fetch wrapper and a typed event emitter.24 min
  5. Lesson 04Utility, Mapped and Conditional TypesBuilt-in helper types, mapped and conditional types, infer, template literal types, and when not to be clever.28 min
  6. Lesson 05Modules, Declaration Files and tsconfig in Real ProjectsES modules versus CommonJS, moduleResolution, paths, .d.ts files, @types, project references, and tsconfig for Node, Vite and Next.js.25 min
  7. Lesson 06TypeScript with React, Node and Runtime ValidationTyped React and Express, plus Zod validation and branded types, because types vanish at runtime.30 min
  8. Lesson 07Common Errors, Strictness Migration and Reading Error MessagesReading long errors bottom-up, the common error codes, and a measured step-by-step migration to strict mode.25 min

Glossary

17 terms used in this series. Inside any lesson, hover or tap a dotted term to see its meaning without leaving the page. Browse all terms →