Code RoomBatch job overlapping runs race
MediumPrep Room Coding #4139

Batch job overlapping runs race

Vibe & agenticAlgorithms & data structuresMid–Senior~18 min

You asked an AI to write a TypeScript batch job (runs every minute on cron) that picks up unsent notifications and dispatches them. It looks clean. Review it for safety under overlapping runs.

The cron sometimes runs slowly. What's the failure mode and how do you fix it?

Implement
claim_notifications(claim_attempts: list[str], batch_limit: int) → list[str]
Examples
in[["w1|n1","w2|n1","w1|n2"],5]out["w1|n1","w1|n2"]
in[["w1|n1","w1|n2","w1|n3","w2|n4"],2]out["w1|n1","w1|n2","w2|n4"]
What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it (tests, edge cases, reading critically), and how you’d re-prompt or decompose to get it right.

0:00 of about 18 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.