Frameworks are useful, but it is worth occasionally revisiting what they abstract away. This post is based on my original Medium article, Creating a NodeJS project without frameworks in 2023.
The project builds a small backend API with Fastify, Prisma, Zod, JWT auth, Vitest, and GitHub Actions.
The stack
The project uses:
- Fastify for HTTP
- Prisma for database access
- Zod for environment and payload validation
- bcrypt for password hashing
- JWT for sessions
- Vitest for unit and e2e tests
- Supertest for HTTP assertions
It is not framework-free in the sense of zero libraries. It is framework-light: the structure is assembled manually.
App setup
The Fastify app registers routes, configures JWT, and defines a centralized error handler. Zod handles validation errors with a clean response.
Environment variables are parsed through a Zod schema so invalid configuration fails early.
Use cases and repositories
The project still uses useful architecture ideas:
- controllers handle HTTP
- use cases hold business behavior
- repositories isolate database access
- factories wire concrete dependencies
That mirrors patterns you might use inside NestJS, but without the NestJS module system.
Testing
Unit tests use in-memory repositories. E2E tests run through Fastify and Prisma. GitHub Actions runs both pipelines so the project keeps feedback in CI.
Takeaways
Building without a full framework is a good reminder of what frameworks provide: dependency injection, module structure, lifecycle hooks, and convention. After writing the wiring manually, it is easier to appreciate why NestJS exists.