C# Backend Developer
Ace your C# Backend Developer interview
Practice real backend interview questions — .NET, APIs, databases, multithreading, and system design. Get your personalized interview action plan.
Start Your Interview TestWhat you will achieve
Backend outcomes that transform your interview performance
Master API and service design
Explain REST, versioning, idempotency, and resiliency patterns with clarity.
Show strong data fundamentals
Choose isolation levels, model aggregates, and write efficient queries.
Handle concurrency confidently
Use queues, batching, throttling, and proper synchronization primitives.
Communicate system design trade-offs
Discuss scaling, observability, failure modes, and operational readiness.
Solid knowledge of ASP.NET Core and EF Core. Some gaps in resiliency patterns and observability.
ASP.NET Core
85%
Data & Transactions
82%
Concurrency
78%
Resiliency & Observability
72%
Take the Backend Readiness Test
In less than 5 minutes, you'll get:
Backend Interview Readiness Score
API design and data modeling insights
Concurrency and resiliency assessment
Action plan to improve critical backend skills
Why backend candidates improve fast
A method focused on clarity and reliability
Real interview simulation
Practice API and system design scenarios.
AI feedback that matters
Improve architecture, data, and resiliency answers.
Personalized scripts
Tailored to your experience and target role.
Questions you will practice
Real C# Backend Developer interview questions you're likely to be asked
Design a high-throughput REST API in ASP.NET Core with proper validation, authentication, and rate limiting.
ASP.NET Core
Explain EF Core change tracking and when to use AsNoTracking for read-heavy endpoints.
EF Core
How would you implement idempotency for POST endpoints to avoid duplicates in distributed systems?
System Design
Redis
Describe strategies to handle concurrency in .NET when processing background jobs (queues, batching, throttling).
.NET
Queues
How do you choose SQL isolation levels for order placement and why?
SQL
Sketch a simple microservice architecture with API gateway, auth, services, and async communication.
System Design
ASP.NET Core
Tech stack covered
Tailored practice for backend and system design
Questions matched to your backend stack
Real-world API and data scenarios
Performance, resiliency, and architecture patterns
Focus on shipping reliable services
.NET & Frameworks
.NET
ASP.NET Core
EF Core
C#
Data & Storage
SQL
NoSQL
Redis
Queues
Architecture & Resiliency
System Design
Circuit Breaker
Retry & Backoff
Logging/Tracing
Testing & Quality
Unit Tests
Integration Tests
Contract Tests
Who this is for
Designed for experienced backend engineers
See the type of backend feedback you'll get
Precise, actionable insights about APIs, data, and resiliency
How would you improve performance for a read-heavy endpoint?
I'd add in-memory caching and increase DB resources.
Consider distributed caching (e.g., Redis) with appropriate TTLs to reduce DB pressure across instances. Profile the endpoint first (logging, tracing, metrics) to locate bottlenecks. Use pagination, projection (select only needed fields), and AsNoTracking for EF Core. For heavy serialization, optimize DTOs and consider compression for large payloads.
How would you design a resilient external service call in .NET?
I'd add retries with a longer timeout.
Retries alone can amplify failures. Add exponential backoff, jitter, and a circuit breaker to prevent cascading issues. Combine with timeouts and fallback paths. Log structured context (correlation IDs) and emit metrics to observe error rates and latency.
Choose your interview preparation plan
Everything you need to stand out and get the job
Monthly Plan
Consistent improvement with structured interview coaching and personalized practice.
Includes:
Full access to all simulations
Unlimited answer reviews
CV-based answer optimization
Confidence score tracking
Salary negotiation preparation
Advanced Plan
For people seeking long-term career growth and comprehensive interview preparation.
Includes:
Custom interview roadmap
New features & simulations added regularly
Priority support
Early access to new tools
FAQ
Senior and lead backend roles focused on .NET, APIs, data modeling, concurrency, resiliency, and system design.
Yes. You'll practice SQL vs NoSQL decisions, isolation levels, EF Core tips, caching, and data consistency patterns.
You get scenarios on retries, circuit breakers, timeouts, fallbacks, logging, tracing, and metrics to keep services reliable.
You can emphasize APIs, databases, or system design, and repeat answers with instant AI feedback anytime.
