Clean code is as important as working code. Modular architecture ensures your backend remains maintainable as it scales.
1The Router mini-app
Think of an express.Router as a mini-application. You can define routes, use middleware specific to that router, and then mount it in your main app using app.use('/path', myRouter).
2Separation of Concerns
By moving logic into Controllers, your route files stay clean—they only list the endpoints and their corresponding handlers. This makes it much easier to find and update specific features.
3The Request Lifecycle
Understanding how a request moves from the main app, through the router, and finally to the controller is key to debugging. Each step in the pipeline can modify the request or end it entirely.
