You are building an API using Express.js, and you want to ensure that the client receives meaningful error messages when something goes wrong. How would you structure your error-handling middleware to achieve this?

To ensure that clients receive meaningful error messages, you should structure your error-handling middleware to create custom error classes and send detailed error messages. This allows you to provide specific information about the nature of the error, making it easier for clients to understand and handle errors gracefully. Sending generic error messages or using status code 200 for all errors would not provide meaningful information to clients. Logging errors to the console only is not sufficient for client communication.