ASP.NET MVC interview questions and answers

It marks a property as required for binding success, separate from [Required] validation messages.

OnActionExecutionAsync wraps the action

Set context.Result in OnActionExecuting to skip the action body.

Return PartialView with a model fragment.

I often return 400 with HTML or JSON errors the client understands.

Cache tag helpers or IMemoryCache around view component output.

I send Content-Security-Policy frame-ancestors or X-Frame-Options DENY.

Challenge triggers the authentication flow like login redirect.

Authenticated cookies renew when half the lifetime passes on activity.

It adds cross-property validation on the model class.

Assert RedirectToActionResult controller and route values.

A culture provider reads cookie or Accept-Language and sets CultureInfo.

Blocking calls during render hold request threads.

Reusable HTML patterns with server logic, like environment banners or CDN script tags.

Group controllers, views, and models by feature instead of by technical type.

I sanitize with a vetted library and still encode by default.

After loading the resource I check ownership or ACL in a filter or service.

I measure action time, EF queries, and view render separately with MiniProfiler or Application Insights.

Chunked uploads or direct-to-blob with a short-lived SAS, plus a complete callback to the app.

Lock after N failed attempts with a cooldown and clear messaging.