Backend mock interviews
Backend rounds tend to start from something you have built and push until it breaks. The interesting part is not the design you present; it is what you say when asked what happens when a dependency stops answering.
AI rounds from ₹49 · Live mocks with a working engineer from ₹999 · Pay per session
What a Backend round covers
API design
Resource shape, status codes that mean what they say, idempotency, and versioning you can live with. Expect to defend a choice rather than list REST conventions.
Data modelling and queries
Schema decisions and their cost later, indexing, and the N+1 that shows up under load. You may be asked to reason about a slow query without seeing the plan.
Concurrency and consistency
Race conditions, locking, transactions and what "at least once" costs you. Booking and payment flows are common ground here because the failure modes are concrete.
Failure and observability
Timeouts, retries and backoff, and what you would need in the logs at three in the morning. Answers that assume the happy path get followed up hard.
What the interviewer is listening for
The signal is whether you reason about failure before you are prompted to. Candidates who name the failure mode themselves — and say which one they chose to accept — consistently score above those who only handle it when pushed.
Where candidates lose marks
- Designing only the happy path and waiting to be asked about errors.
- Reaching for a queue or a cache without saying what problem it solves.
- Describing a system you worked on without being able to say why it was built that way.
Two ways to practise
An AI round, on your own
One question at a time with real follow-ups on what you actually said. Choose three, five or eight questions. Scored the moment you finish, with a written breakdown across technical depth, problem solving and communication.
A live mock with an engineer
Forty minutes over Zoom with someone who runs backend interviews for a living. They score five criteria and write up what to fix, and you keep a numbered certificate for the session.
Pick your stack for an AI round: Node.js · Java · Python · PHP · Rails · Ruby.
Other tracks
Not sure which to book? The FAQ covers how sessions are scored, and candidate stories show what people did with the feedback.