What common mistake do developers make with Middleware ordering, why does the mistake cause problems, and what is the safer approach?

What common mistake do developers make with Middleware ordering, why does the mistake cause problems, and what is the safer approach? One recurring problem with middleware ordering is applying it without understanding the boundary it protects. Putting business-domain calculations into middleware just because middleware runs on every request. In addition, The order in which middleware executes can affect authentication, session state, request transformation and response behavior. Safer engineering approach: keep the responsibility in the correct layer, use the framework's supported API, validate and authorize inputs, avoid hidden side effects, and verify the behavior with tests.