One Bad Executor

A medium AI Coding mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.

Domain
AI Coding
Difficulty
medium
Seniority
L5

Interview Prompt

Our nightly orders enrichment job ran 3h 40m last night instead of its usual 22 minutes, with one executor OOMing on stage 4 and cluster spend tripling, even though order volume grew only about 8% week-over-week. Fix the job in jobs/ so tests/test_skew_observability.py passes using only what the production cluster will actually accept, and be ready to defend your trade-offs against a different data shape.

Summary

One node held the whole night hostage.

How This Interview Works

  1. Read the task and the repository: the files, the failing check and the constraints
  2. Work the fix with the AI agent at your side, and run the checks until they pass
  3. Submit, then answer the interviewer's questions about the change you made
  4. Get a hire or no-hire decision with feedback on how you drove the agent