All styles
Playbook · Interview style
Backend deep-dive
The classic senior-backend screen: design an API, model the data behind it, and defend the choices when the load goes up. Expect to be pushed on where the bottleneck really is, not just whether the endpoint returns 200.
- APIs
- Databases
- Caching
- Scaling
Interview flow
A style plays out as a sequence of sessions — start each one on its own; your readiness rolls up across them.
- 1. Depth interviewThe core backend depth round — APIs, data model, and scaling.Start below
- 2. Code challengeFix a realistic backend bug in place, then see it diffed.
What interviewers usually probe
- How your data model holds up as the table grows — indexes, N+1, hot rows.
- Where you'd add a cache and what it costs you in correctness.
- What actually breaks first under load, and how you'd find it.
- API contract choices: pagination, idempotency, versioning.
What we assess
- REST API design and contract decisions
- Relational data modelling and query performance
- Caching, consistency, and read/write trade-offs
- Reasoning about bottlenecks under load
What we don’t
- Algorithmic (DSA) roundsWe don't do LeetCode-style puzzles — practise those on LeetCode or HackerRank, then come here for the depth rounds.
- Behavioural / leadershipThis is a technical depth screen, not a values or management interview.
Practise this style
Run an adaptive backend deep-dive interview — pick your level, answer by voice or text, and get corrected like a senior engineer. Your first interview is free.
Practise Backend deep-dive