How does the ASP.NET Core request pipeline work when a request enters the application?

Explain the ASP.NET Core request pipeline

Explains how an HTTP request flows through ASP.NET Core middleware, routing, endpoint execution, and response generation.

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TL;DR

The ASP.NET Core request pipeline is a sequence of middleware components that process the incoming request and outgoing response. Each middleware can inspect the request, call the next component, add behavior, or stop the request early. Routing selects the endpoint, and then the endpoint executes controller, minimal API, or other handler logic. The order matters because authentication, authorization, error handling, and CORS depend on where they run.

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Practice focus

Middleware order, endpoint routing, short-circuiting, cross-cutting concerns, and production request behavior.

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Core answer first, then checkpoints toward a stronger answer.

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Core answer
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Why this question matters
This drill checks whether the candidate understands the actual path of a request, not only controller code. Many production bugs around authentication, CORS, error handling, routing, and logging come from pipeline configuration rather than business logic.
The ASP.NET Core request pipeline is a sequence of middleware components that process the incoming request and outgoing response. Each middleware can inspect the request, call the next component, add behavior, or stop the request early. Routing selects the endpoint, and then the endpoint executes controller, minimal API, or other handler logic. The order matters because authentication, authorization, error handling, and CORS depend on where they run.
Checkpoint
Stronger answer
Optional upgrade with examples, trade-offs, and sharper phrasing.
In a real API, I think of the pipeline as the place where cross-cutting infrastructure behavior is applied consistently. For example, exception handling should run early so it can catch failures from endpoints, authentication should run before authorization, and correlation logging should wrap the whole request. The trade-off is that middleware is powerful but broad; if I hide feature-specific business rules in middleware, debugging becomes painful because the behavior is no longer visible at the endpoint.

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Common mistakesCandidateCommon mistakesMistakes that weaken the answer or signal shallow understanding.Open details

Details

Treating middleware order as cosmetic.
Putting authorization before authentication.
Hiding business rules in global middleware.
Ignoring short-circuit behavior.
Debugging controllers when the request never reaches a controller.

How does the ASP.NET Core request pipeline work when a request enters the application?

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