ASP.NET Core Middleware Pipeline

What common mistakes do candidates make around ASP.NET Core Middleware Pipeline, and how do you avoid them?

Answers use simple, clear English.

Quick interview answer

Common mistakes: Placing UseAuthentication after UseAuthorization; forgetting UseRouting. Best practices: Follow Microsoft template order; use MapWhen for branch pipelines.

Detailed answer

Common mistakes: Placing UseAuthentication after UseAuthorization; forgetting UseRouting. Best practices: Follow Microsoft template order; use MapWhen for branch pipelines. Core: Request flows through middleware chain: Exception → HTTPS → Routing → Auth → Endpoints. Each can short-circuit or call next(). Order matters critically. Real-time example: Custom correlation ID middleware adds X-Request-Id header before logging middleware runs. Pros: Composable cross-cutting pipeline; same model for minimal APIs and MVC. Cons: Wrong order breaks auth/CORS; async middleware must await next(). Common mistakes: Placing UseAuthentication after UseAuthorization; forgetting UseRouting. Best practices: Follow Microsoft template order; use MapWhen for branch pipelines. Audience level: Tech Lead.

Full explanation

Request flows through middleware chain: Exception → HTTPS → Routing → Auth → Endpoints. Each can short-circuit or call next(). Order matters critically.

Real example & use case

Custom correlation ID middleware adds X-Request-Id header before logging middleware runs.

Pros & cons

Pros: Composable cross-cutting pipeline; same model for minimal APIs and MVC. Cons: Wrong order breaks auth/CORS; async middleware must await next().

ASP.NET Core Middleware Pipeline

Quick interview answer

Detailed answer

Full explanation

Real example & use case

Pros & cons

Common mistakes

Best practices

Follow-up questions