.NET and C# interview questions

Join is inner join of matching pairs.

NetTopologySuite with EF spatial providers stores points and polygons.

Arrange, Act, Assert keeps tests readable.

UseResponseCompression with Brotli or Gzip for compressible MIME types.

Rolling updates with health checks, backward-compatible migrations, and dual-run periods.

It limits a value between min and max in one call.

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

Rent a buffer, use only the counted slice, and return in finally.

It adds a global LINQ filter, often for soft delete or tenant.

IHostedService or BackgroundService for in-process jobs.

INumber and friends let algorithms work across numeric types.

It sorts largest-first by a key selector.

I emit CSP headers via middleware with nonces for scripts.

It returns 200 with an optional body.

It runs set-based updates without loading entities.

A central identity provider issues tokens all APIs validate with the same authority.

Culture-insensitive case-insensitive compare, good for codes and paths.

Parameters can accept JSON automatically or use [FromBody].

The runtime starts with quick JIT then recompiles hot methods more optimally.

A tiny post-deploy check that the site boots and a critical path works.