The Node.js Advantage
Node.js uses a non-blocking, event-driven architecture, making it incredibly fast for I/O intensive tasks (like reading from a database or calling other APIs). However, if structured poorly, an Express app can turn into unmaintainable spaghetti code.
Controller-Service-Repository Pattern
Never write database logic directly inside your Express routes. Separate your concerns:
- Controllers: Handle HTTP requests and responses (res.status(200).json(...)).
- Services: Contain the core business logic and rules.
- Repositories (or ORM like Prisma): Handle the actual SQL queries.
Centralized Error Handling
Instead of writing `try/catch` blocks in 100 different routes, create a global error handling middleware. Catch all asynchronous errors and pass them to a single function that logs the error securely and sends a clean '500 Server Error' to the user.