NestJS

NestJS is a server-side framework for Node.js, written in TypeScript, with a defined architecture: modules, dependency injection, and a clear split between controllers, services and data access.

Where it fits

Node.js leaves structure to each team, so two services written by two teams can look very different. That slows onboarding and makes moving between codebases harder. NestJS sets the structure, so a developer who knows the framework can open an unfamiliar NestJS codebase and find things where they expect them. This helps most on systems maintained for years by a changing team.

Dependency injection makes components easier to test, and modules keep boundaries between parts of the system clear. Official packages cover validation, configuration, scheduled and queued jobs, and OpenAPI documentation, so those choices are made the same way across services.

Its limits

There is more structure and more to learn up front, including decorators and dependency injection. For a small service with a short life, that overhead is often not repaid, and a lighter framework such as Express or Fastify is enough.

How we use it

We use it for backend services and APIs on larger systems, where several developers work on the same codebase over a long period.

Related

Enterprise Software Development, System Integration & API Development