Building Scalable APIs with NestJS

# Building Scalable APIs with NestJS NestJS is a progressive Node.js framework for building efficient and scalable server-side applications. It uses TypeScript and follows architectural patterns similar to Angular. ## Why NestJS? - **TypeScript First**: Full TypeScript support out of the box - **Modular Architecture**: Organize code into modules, controllers, and services - **Dependency Injection**: Built-in DI container for better code organization - **Decorators**: Use decorators for routing, validation, and more - **Extensible**: Works with Express or Fastify under the hood ## Core Concepts ### Modules Modules are the basic building blocks of a NestJS application. Each module encapsulates related functionality. ### Controllers Controllers handle incoming requests and return responses to the client. ### Services Services contain business logic and can be injected into controllers or other services. ## Best Practices 1. Keep modules focused and cohesive 2. Use DTOs for data validation 3. Implement proper error handling 4. Use guards for authentication and authorization 5. Write unit and integration tests ## Conclusion NestJS provides a solid foundation for building enterprise-grade applications with TypeScript.