When would you use middleware instead of filters in ASP.NET Core?

In production I choose the earliest boundary that has all required context and no broader reach than necessary. Ordering is explicit: exception handling must wrap downstream failures, forwarded headers must run before components that use scheme or client address, and authentication must establish identity before authorization. Filters have their own ordering and short-circuit behavior, so global, controller, and action registrations need a documented convention. I test requests that fail before routing, during binding, inside the action, and while writing the result, then verify telemetry is emitted once and the response contract remains consistent. Cross-cutting code earns its place only when ownership and execution order remain obvious during an incident.