ASP.NET Core Interview Question #77

How does the ASP.NET Core request pipeline work?

Middleware & Request Pipeline Mid-Level Intermediate

Quick Interview Answer

When an HTTP request reaches an ASP.NET Core application, it passes through an ordered sequence of middleware components. Each component decides whether to call the next component in the pipeline.

Detailed Explanation

When an HTTP request reaches an ASP.NET Core application, it passes through an ordered sequence of middleware components. Each component decides whether to call the next component in the pipeline.

A middleware can perform work before calling next, await the downstream pipeline, and then perform additional work after downstream processing completes. A component can also short-circuit the pipeline by generating a response without calling the next middleware.

This pipeline model provides a flexible way to implement cross-cutting HTTP concerns without putting them inside controllers or business services.

Code Example

app.Use(async (context, next) =>
{
    Console.WriteLine("Before next middleware");

    await next();

    Console.WriteLine("After next middleware");
});