Why does the order of middleware matter so much?

Middleware executes in the exact order in which it is registered. Because each middleware can decide whether to pass control to the next component, incorrect ordering can break critical behaviors.

For example:

• Exception-handling middleware must be early in the pipeline to catch downstream errors.
• Authentication must run before authorization and MVC.
• Static file middleware should run before MVC to avoid unnecessary controller execution.

ASP.NET Core does not automatically correct the order, so developers are responsible for composing the pipeline correctly.