Clean Architecture in NestJS — A Practical Guide

Building NestJS apps is easy. Building NestJS apps that are still easy to change six months later is a different story. Clean Architecture gives you a way to structure your code so that business logic doesn't bleed into HTTP handlers, database queries don't dictate your domain model, and swapping infrastructure (say, Postgres → SQLite, or REST → gRPC) doesn't require rewriting half the app. This guide is practical. We'll build a small feature — managing User entities — and walk through each laye