NestJS Tutorial

1. NestJS Introduction

What NestJS is, why teams choose it over plain Express, installing the CLI, and the generated project structure.

2. Controllers and Providers

Controllers with @Controller()/@Get()/@Post(), providers with @Injectable(), and constructor-based dependency injection.

3. Modules and Dependency Injection

@Module(), how Nest's DI container resolves dependencies, and organizing a larger app into feature modules.

4. Guards, Pipes and Interceptors

Guards for authorization, Pipes for validation with ValidationPipe and DTOs, and Interceptors for wrapping request handling.

5. Testing with Jest

Unit testing a service with a mocked dependency, and e2e testing a controller with supertest.

6. Microservices with NestJS

Nest's built-in microservice transport layer — TCP, Redis and Kafka — and one service calling another.

7. NestJS Interview Questions

Real NestJS interview questions and answers covering DI, modules, guards, pipes, interceptors, and decorators.