⚙️Skill assessment · 180 questions

Backend Engineering skill assessment

APIs, auth, data, and reliability at scale.

Take the assessment →🧑‍🏫 Learn hands-onProfessional→

What it covers

HTTP & REST APIs

Master HTTP semantics and REST conventions so your APIs are predictable and easy to consume. Every backend interview probes status codes, verbs, and resource design.

HTTP methods and idempotencyStatus codes and when to use themResource modeling and URL designAPI versioning strategiesPagination, filtering, and sorting

Auth & Security

Understand authentication and authorization patterns so you can protect APIs without locking out legitimate users. Auth mistakes are the most common — and most costly — backend security failures.

Sessions vs. tokens vs. JWTsOAuth2 and OpenID Connect flowsPassword hashing and storageInput validation and sanitizationOWASP Top Ten vulnerabilities

Data & Persistence

Learn how a backend service manages its relationship with the data layer, from schema evolution to connection handling. Getting this wrong causes outages and data loss, not just slow queries.

ORMs vs. raw SQL tradeoffsSchema design and normalization basicsMigrations and zero-downtime schema changesConnection pooling and pool sizingTransactions and consistency guarantees

Caching & Performance

Learn where to cache and how to invalidate correctly, since caching is the highest-leverage performance fix — and the easiest way to serve stale data. Spotting N+1 queries before they hit production is a core backend skill.

Cache layers: CDN, app, databaseCache invalidation strategiesN+1 query detection and fixesRead-through and write-through cachingProfiling and identifying bottlenecks

Async & Messaging

Understand queues and pub/sub so long-running or bursty work doesn't block your API. Idempotency and delivery guarantees separate reliable async systems from ones that silently drop or duplicate work.

Message queues vs. pub/subBackground job processingAt-least-once vs. exactly-once deliveryIdempotency keys and deduplicationDead-letter queues and retries

Architecture & Reliability

Learn how to design service boundaries and failure handling so one broken dependency doesn't take down the whole system. Retries, timeouts, and observability are what separate production-grade backends from prototypes.

Service boundaries and couplingTimeouts, retries, and backoffCircuit breakers and graceful degradationHealth checks and readiness probesLogs, metrics, and distributed tracing

Ready to benchmark your Backend Engineering skills?

180 questions · about 5 minutes · see your level and percentile instantly.

Take the assessment →

Explore other assessments

🤖AI Engineering 🧑‍💻AI for Coding 🧠Building AI on the Cloud ☸️Kubernetes ☁️AWS Cloud 🎨Frontend Engineering 🗄️Databases 📦Containerization 🔐Security & DevSecOps 🏗️Terraform & IaC 📊Observability & Monitoring 🐍Python 🚀CI/CD & Delivery Pipelines 🔁GitOps & Delivery 🧩System Design 🐧Linux & the Command Line 🔷Microsoft Azure 🌥️Google Cloud 📜Shell Scripting