Tracks / Backend
Backend
APIs, idempotency, caching, queues, and designing for the retry.
mid
Working knowledge. Where most loops are decided.
- API design & HTTP semantics10 questions
REST vs RPC vs GraphQL, status codes, idempotency, versioning, pagination, and errors that clients can act on.
senior
Trade-offs and failure modes under follow-up pressure.
- Caching, queues & scaling10 questions
Cache strategies and their failure modes, message queues, backpressure, and how services fail in production.
- The incident round Signal6 questions
Six production symptoms with no stack trace. The interviewer describes what users see and watches how you narrow it down.
staff
Judgement, scope and the questions with no clean answer.
- Distributed correctness Signal6 questions
Exactly-once, ordering, clock skew, split brain, and saga rollback — the questions where the confident answer is usually wrong.
- The network path of one request Deep8 sections
DNS, TCP, TLS, HTTP/2 and /3, proxies, keepalive and connection pools — why timeouts, retries and p99 behave the way they do.