Discuss how you would design a centralized error handling mechanism in a Go application.

Designing a centralized error handling mechanism in a Go application typically involves creating custom error types and using a middleware approach. This allows you to have consistent error handling logic across your application. It ensures that you can handle errors gracefully and provide meaningful feedback to users or log errors effectively. The use of panic should be limited to exceptional cases, and the use of if err != nil checks in every function is not considered a best practice for centralized error handling.