Error Handling That Doesn't Embarrass You in Production
The scariest thing in production is not that errors happen. It is that the wrong information leaks when they do.
In Fiber v3, the default error handler sends err.Error() to the client, which can expose a raw database error, an internal file path, or other library-generated details. Panics are a separate concern: Fiber does not recover them by default, so they crash the process unless you enable the Recover middleware. During development, that kind of visibility is helpful. In production, it is a security incident waiting to happen. An attacker learns your ORM, your table schema, maybe even the specific query that failed. All from a 500 response you never thought anyone would read.
Fiber v3's error handling is designed around one idea: handlers return errors, and a central handler decides what the client sees. That separation sounds simple, but it changes how you structure error responses across your entire application.