.NET and C# interview questions

The proxy sends X-Forwarded-For and Proto

It switches from IQueryable to in-memory LINQ from that point.

I use WebApplicationFactory Customize and ConfigureAppConfiguration to inject test settings.

Always parameterize user input.

Complex types bind from route, query, and body based on attributes like FromRoute.

HttpOnly, Secure, SameSite, and tight expiration.

Browser cookie sessions need antiforgery on state-changing calls.

It can avoid allocating a Task when results are often synchronous.

Join is inner join of matching pairs.

UseResponseCompression with Brotli or Gzip for compressible MIME types.

Pinning blocks MITM but breaks when certs rotate if pins are stale.

IHostedService or BackgroundService for in-process jobs.

It runs set-based updates without loading entities.

Parameters can accept JSON automatically or use [FromBody].

Update secrets store, recycle apps to pick new values, then retire old creds.

It forces object initializers to set the property.

Data annotations or FluentValidation with ModelState checks.

Loading a collection then querying each child lazily.

A singleton holding a scoped service outlives the scope and uses disposed objects.

In-memory or SQLite providers, or wrap with a repository fake.