.NET Backend

Abstraction versus encapsulation in C#

Separates hiding implementation complexity from controlling access to state, with practical examples where both ideas work together.

Access modifiers and assembly boundaries in C#

Uses public, internal, protected, private, and protected internal deliberately to control API surface and inheritance exposure.

ActionResult vs typed results in ASP.NET Core APIs

Compare controller ActionResult patterns with minimal API typed results and explicit HTTP outcomes.

Add a regression test after a role-specific incident

Turns a production-only role and payload failure into the smallest durable API regression test.

Add guardrails around EF Core tenant query filters

Explains how tenant query filters help, where they can be bypassed, and what extra safeguards protect tenant isolation.

ADO.NET connection pooling and pool exhaustion

Explains physical connection reuse, pool partitioning, short ownership, exhaustion causes, diagnostics, and why increasing the pool is not the first fix.

.NET Backend

Backend-focused .NET interview preparation.

A backend-focused .NET preparation path covering C#, ASP.NET Core APIs, data access, reliability, testing, and practical coding.

C# Practical Coding Problems

Hands-on coding rounds with practical C# data, API, and reliability exercises.

A practical C# coding interview track covering strings, dictionaries, grouping, parsing, pagination, validation, rate limiting, retry, caches, log aggregation, and edge-case thinking.

ASP.NET Core Practical API Labs

Build the endpoint, protect its boundaries, and make failure behavior explicit.

A hands-on ASP.NET Core interview track covering typed contracts, validation, list queries, overposting, idempotency, concurrency, bulk writes, capability and resource authorization, secure files, downstream calls, durable jobs, webhooks, and rate limiting.

EF Core Practical Data Access Labs

Implement, inspect, and debug the data-access code behind real .NET APIs.

A hands-on EF Core interview track covering DTO projections, N plus one fixes, optional filters, keyset pagination, split queries, set-based updates, concurrency conflicts, outbox transactions, retry strategies, cancellation, bounded imports, query diagnostics, and pooled tenant state.