Comparing NestJS and FastAPI for Backend Development

For the past 4 days I've been learning NestJS — decorators, controllers, dependency injection. Today I decided to explore FastAPI in parallel. Not because I'm abandoning NestJS. But because good backend developers shouldn't be locked to one ecosystem. Here's what I discovered on Day 1 👇 The concepts are surprisingly similar: NestJS uses @Controller() and @Get() decorators. FastAPI uses @router.get() — same decorator pattern, Python syntax. NestJS uses DTOs with class-validator for input validation. FastAPI uses Pydantic models — cleaner, built into Python's type system. NestJS requires Swagger setup manually. FastAPI generates interactive API docs automatically at /docs. No config needed. What genuinely impressed me: FastAPI's speed. It's one of the fastest Python frameworks — async by default, built on Starlette. For data-heavy backends and ML integrations, it makes a lot of sense. My honest take after Day 1: If you know NestJS, FastAPI is not scary. The mental model transfers. You're just learning Python idioms, not a new way of thinking about backend architecture. The best backend developers I've seen are polyglot — they pick the right tool for the job, not the tool they're most comfortable with. That's the skill I'm building. Day 2 of FastAPI tomorrow. Following along? Drop a comment — would love to connect with others exploring both ecosystems. #FastAPI #NestJS #Python #BackendDevelopment #LearningInPublic #SoftwareEngineering #NodeJS #100DaysOfCode #WebDevelopment

  • graphical user interface, application

To view or add a comment, sign in

Explore content categories