A complete, step-by-step TypeScript tutorial series. From your first program to building full-stack applications with React, Node.js, and Next.js. Every article has working code you can copy and run.

No complicated theory. Just simple explanations and real code.


Part 1: Foundations (Tutorials #1–#8)

Learn the building blocks of the TypeScript language.

#TutorialWhat You Will Learn
1What is TypeScript? Why Use It in 2026?Why TypeScript matters, who uses it, what you can build
2Installation and SetupNode.js, npm, VS Code setup, tsconfig.json, first program
3Basic Typesstring, number, boolean, arrays, tuples, any, unknown
4Functions and Type AnnotationsParameter types, return types, arrow functions, overloads
5Objects and InterfacesObject types, interfaces, extending, interface vs type
6Union Types, Literal Types, and Type AliasesUnion types, literal types, discriminated unions
7Enums and Const AssertionsEnums, const enums, as const, satisfies
8Type Narrowing and Type Guardstypeof, instanceof, custom type guards, exhaustive checks

Part 2: Intermediate (Tutorials #9–#16)

Build stronger programs with generics, classes, modules, and async patterns.

#TutorialWhat You Will Learn
9GenericsGeneric functions, interfaces, constraints, keyof
10Classes and Access Modifierspublic, private, protected, abstract classes
11Modules and Namespacesimport, export, type-only imports, declaration files
12Utility TypesPartial, Required, Pick, Omit, Record
13Mapped Types and Conditional TypesCustom mapped types, infer, template literal types
14Error Handling PatternsResult types, type-safe errors, error boundaries
15Async/Await and PromisesPromise types, async functions, error handling
16DecoratorsClass decorators, method decorators, parameter decorators

Part 3: Practical (Tutorials #17–#22)

Apply TypeScript to real frameworks and tools.

#TutorialWhat You Will Learn
17TypeScript with ReactProps, state, events, hooks with types
18TypeScript with Node.jsExpress/Fastify, typed APIs, middleware
19TypeScript with Next.jsApp Router, Server Components, typed routes
20Zod and Runtime ValidationSchema validation, type inference from schemas
21tRPC — End-to-End Type SafetyType-safe APIs without code generation
22Testing with TypeScriptVitest, type testing, mocking

Part 4: Advanced and Projects (Tutorials #23–#25)

Advanced patterns and a real project.

#TutorialWhat You Will Learn
23Advanced PatternsBranded types, builder pattern, type-safe event emitter
24tsconfig Deep DiveEvery important compiler option explained
25Project — Full-Stack AppBuild a complete app with React, Node.js, tRPC, and Zod

Who is This For?

  • JavaScript developers who want to add TypeScript to their skills
  • Developers from other languages (Python, Go, Rust, Kotlin) who want to build type-safe web apps
  • Beginners who want to learn a modern, in-demand language
  • Anyone who learns better by building real things instead of reading documentation

How to Use This Series

Start from Tutorial #1 and go in order. Each tutorial builds on the previous one. If you already know the basics, jump to Part 2 (Tutorial #9) for intermediate patterns.

Source Code

All code from this series is on GitHub: kemalcodes/typescript-tutorial