.NET and C# interview questions

A delegate is a type-safe function pointer.

Generics keep type safety and avoid boxing of value types.

Transient is a new instance every resolve.

The context snapshots entity instances and generates INSERT, UPDATE, or DELETE on SaveChanges.

I Include the navigation I need, or project to an anonymous type or DTO in one Select.

Ref passes a variable that must already be assigned and can be read and written.

Records are reference types with value-based equality and a concise init syntax.

Exceptions are for unexpected failures

The pool reuses worker threads for Tasks and I/O completions.

The GC frees unreachable objects, but event handlers, static caches, and forgotten subscriptions keep objects reachable.

Gen 0 is nursery for short-lived objects

Span is a stack-only view over contiguous memory so I can slice arrays and strings without extra allocations.

ConfigureAwait false skips capturing the SynchronizationContext, which avoids deadlocks in libraries that wait on Tasks.

I keep the context short-lived, batch SaveChanges, disable tracking for reads, and consider ExecuteUpdate for bulk.

Not in source or appsettings committed to git.

I start with traces and a profiler, not guesses.

Classes are reference types on the heap

Properties expose get and set accessors like fields but with control.

Async await frees threads while waiting on I/O without blocking.

The Common Language Runtime runs .NET bytecode, handles memory with GC, and provides security and type safety.