Middleware

Canonical guidance

• keep middleware focused
• preserve request context and ownership
• make chain order intentional

Use when

• logging
• panic recovery
• authentication gates
• request metrics or tracing

Avoid

• burying domain logic in wrappers
• middleware that starts detached goroutines
• wrapper stacks so deep that request flow becomes opaque

Preferred pattern

• compose a small chain of focused wrappers around the final handler

Anti-pattern

• one “middleware” that parses config, talks to databases, mutates globals, and serves requests

Explanation: This is tempting because wrappers are easy to stack, but broad middleware becomes hidden application logic.

Why

• middleware is useful only while request flow stays legible