KRAFTJobs
Interview prep

Practice the work behind the question.

Choose a lane and role to see its real interview questions, what each tests, and a framework for strong answers. These are practice prompts and general guidance - not memorized scripts, and not every company interviews the same way.

Backend Engineer

Expect questions about backend engineering, distributed systems basics, and database design, plus a scenario where the role must respond to provider outages, reorg-related inconsistencies, duplicate events, data corruption, security incidents, or failed migrations. Interviewers are looking for evidence that the candidate knows where service architecture and APIs stop and core consensus by default and smart contract audit sign-off begin.

Open the Backend Engineer role guide
  1. Role fundamentals

    How do you make event processing idempotent?

    Common follow-ups

    • Can you give a concrete example?
    • What would you do differently next time?
  2. Role fundamentals

    What happens to your database when a chain reorg invalidates events?

    Common follow-ups

    • Can you give a concrete example?
    • What would you do differently next time?
  3. Judgment

    How would you design around an unreliable RPC provider?

    Common follow-ups

    • Can you give a concrete example?
    • What would you do differently next time?

Weak-answer patterns

  • • Repeating jargon without specifics.
  • • Avoiding concrete examples.
  • • Claiming team outcomes as personal work.
  • • Presenting tools or follower counts as competence.
  • • A CRUD API with 'Web3' added to the title
  • • Services with no observability
  • • Indexers that assume events are never reorganized

Self-review after practicing

ClarityRelevanceEvidenceDecision qualityBoundariesLearning
Build proof for these answers

Prepare with evidence

Build proof-of-workAnswers land better when backed by a real artifact - each role has a matching portfolio brief.Re-read the role guideThe role guide's boundaries and proof standards are exactly what these questions test.Get Hired journeyInterview practice is stage 11 - see how it fits before and after applications.