Question bank

4,310 interview questions, answered.

Reference answers, what the interviewer is really testing, how it is graded, and the follow-ups that come next.

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4,310 questions

  1. 4201If I did know the system they are working with on a daily basis.EasyProduct
  2. 4202Unique Chat ConversationsMediumCodingData
  3. 4203Find the total number of unique paths in a maze from the source to the destination.Medium
  4. 4204Unsold ProductsEasyCodingData
  5. 4205Given an unsorted array, find duplicate elements in constant time, without using inbuilt functions of python.MediumCoding
  6. 4206Validate Bitcoin TransactionsHardCodingData
  7. 4207Video Game MatchmakingMediumCodingData
  8. 4208Walmart Inventory StatusMediumCodingData
  9. 4209What did you do at your last job?EasyBehavioral
  10. 4210What happens when the JVM Garbage Collector releases a property static of a class?MediumTechnical
  11. 4211What is Pyspark?EasyDataSystem design
  12. 4212Why did you choose analytics as a career?MediumBehavioral
  13. 4213Why do you want to work at Rivian?MediumBehavioral
  14. 4214Why do you want to work at Hinge?MediumBehavioral
  15. 4215Review System76's public Backend Engineer product-query API assignment. Explain a plan for data modeling, category filtering, verification, and a concise assumptions note.MediumCodingSystem design· SSystem76
  16. 4216Account A starts at 100 units before this batch. Each accepted event adds its signed delta; these are not full balance snapshots. Durable event identity is (source, event_id), and the first valid accepted payload is immutable. An exact retry has no new effect. A later different payload with the same identity is quarantined and does not replace the accepted event. Corrections must be new authorized events with their own identity and a reference to the original event. All rows below target A and the correction is authorized. Process them in the stated delivery order.MediumDataTechnical
  17. 4217Use Monzo's historical public web-engineer portal task as a practice reference. Explain how you would handle token expiry, app updates, and paginated user lists without stale cross-app state.MediumCodingTechnical· Monzo
  18. 4218You are the founding engineer at the end of your first week on a fictional report product. The agreed pilot outcome is that valid accepted exports produce correct, account-authorized results within five minutes. The following complete observation window covers four pilot accounts and 12 distinct accepted exports: eight completed correctly within five minutes, two completed correctly after five minutes, and two failed. Both failed jobs used the documented, supported format B; you reproduced a parser mismatch with a synthetic B fixture. No other failure cause has been established.HardBehavioralSystem design
  19. 4219A search component keeps the last successful results visible while a newer search is pending. Each request has an increasing request ID. Its success handler checks whether the ID is still active, but its failure and cleanup handlers do not:MediumCodingTechnical
  20. 4220A member of tenant red uploads an untrusted document. An isolated parser extracts text and proposes a title. A red reviewer previews the result; only a red publisher may release a reviewed version. The parser cannot access the network and has a per-job CPU, memory and output-size limit. Storage keeps immutable upload and extraction versions. The preview renders extracted content. Name the trust boundaries, two threats that remain after parser isolation, and negative and positive tests. A parser result must never grant publication authority.MediumTechnical
  21. 4221Assume admins are tenant-scoped, red-admin has no blue membership, and the database worker can read all tenants. Review this pseudocode and write a finding plus regression tests.HardTechnical
  22. 4222A 24 GiB GPU holds13 GiB of weights and reserves3 GiB for runtime. Standard non-MLA attention has 32 layers,8 KV heads,128 head dimension and 2-byte cache values. Every request may hold8,192 input-plus-output tokens. Calculate the simplified concurrency bound and explain why a test at twelve concurrent requests can fail.MediumAI MLSystem design
  23. 4223The same mixed chat/document trace produces 900 output tokens/s with chat p95 gaps 35 ms. A larger batch produces 1,080 tokens/s but chat gaps 70 ms. The chat limit is 50 ms. Decide whether to accept and propose a controlled next test.MediumAI MLSystem design
  24. 4224Eight GPUs are available on four hosts, two per host. The model requires two GPUs per replica. A host-local replica measures40 requests/minute; an eight-GPU group measures110. Demand is 100/minute after one host loss. Compare the two layouts under the assumption that a parallel replica needs every worker.MediumAI MLSystem design