When your Node.js project grows, poor file organization can become a nightmare. You’ll start with a few routes and functions… then suddenly you're digging through a jungle of files just to debug one endpoint. Code becomes harder to read, reuse, and test. That's when bugs hide and productivity drops. The solution? Structure your app with folders for routes, controllers, services, and models. Keep logic separate and follow naming conventions. A clean structure makes scaling easier, onboarding faster, and debugging less painful. Organize early — or refactor later with regret.