Improving error handling in a Node.js app ensures that your app can gracefully recover from unexpected failures and provide useful feedback to users. For synchronous code, use `try/catch` blocks to catch errors and handle them accordingly. In asynchronous code, especially when using promises, chain `.catch()` to handle errors. For async/await, wrap your async functions in `try/catch` to capture errors. Additionally, create centralized error-handling middleware (for example, in Express.js) to catch unhandled errors and respond with meaningful error messages. You can also define custom error classes to better categorize errors. This approach allows for more structured error reporting and logging, improving both debugging and user experience.