Four Million Echoes
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 orders enrichment consumer reprocesses ~4M messages every time we deploy. The team added enable_auto_commit=False and explicit commit() calls weeks ago, so this should have stopped. Run tests/test_offsets_persist.py to reproduce. The reprocess window correlates with rebalance events. Find why the explicit commits aren't sticking and fix it. Bonus credit: explain what 'cooperative-sticky' would have changed.
Summary
It happened. It happened again.
How This Interview Works
- Read the task and the repository: the files, the failing check and the constraints
- Work the fix with the AI agent at your side, and run the checks until they pass
- Submit, then answer the interviewer's questions about the change you made
- Get a hire or no-hire decision with feedback on how you drove the agent