SQS charge duplicate processing
An AI agent wrote this SQS-triggered Lambda (TypeScript) to charge customers from an order queue. Finance reports occasional duplicate charges. The code looks correct. Find the root cause and the fix.
Implement
charge_orders_idempotently(delivered_order_ids: list[str]) → list[str]Examples
in
[["ord-1","ord-2","ord-1"]]out["charged","charged","duplicate_skipped"]in
[["ord-1","ord-1","ord-1"]]out["charged","duplicate_skipped","duplicate_skipped"]in
[[]]out[]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 20 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.
Run or narrate your approach, then ask the coach.