# Review by Andrej Karpathy (Round 1)

---

## Review Complete — Andrej Karpathy

**VERDICT: approve**

### Key Findings

1. **Core fix is correct and minimal.** `triage_message()` is a pure, stateless LLM classification call — holding `agent_lock` across it was serializing Slack intake behind pipeline execution for zero safety benefit. Removing it is a one-concept change with outsized UX impact.

2. **Retry logic has the right error taxonomy.** Transient errors (`TimeoutError`, `ConnectionError`, `OSError`) get 1 retry with 3s backoff. Non-transient errors (`ValueError`, etc.) fail immediately. This is how you handle stochastic API calls — you don't retry on bad inputs, you retry on network weather.

3. **Rate-limit TOCTOU gap is closed.** `increment_hourly_count` now fires atomically inside `state_lock` alongside `check_rate_limit` and `_reserve_pending_message`. Fail-closed: failed triages don't decrement the count.

4. **Redelivery loops prevented.** Both error paths mark the message as `"triage-error"` in `watch_state`, which causes `_handle_event` to reject future Slack redeliveries of the same message.

5. **Test coverage is thorough.** 12 new tests covering every code path — parallel triage with held lock, retry/shutdown interaction, non-transient skip, triage-error marking, redelivery rejection, eager rate limiting, fail-closed behavior, and a full integration test.

6. **No secrets, no unnecessary dependencies, no unrelated changes.** All 20 tests pass.

Review artifact written to `cOS_reviews/reviews/andrej_karpathy/20260331_parallel_slack_intake.md`.