# Review by Andrej Karpathy (Round 4)

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## Review — Andrej Karpathy (Round 4)

VERDICT: approve

FINDINGS:
- [src/colonyos/orchestrator.py]: Prompt design is excellent — dual-constraint pattern ("Implement ONLY task X" + "Do not implement other tasks") uses redundant boundaries that significantly reduce model drift into adjacent tasks. Prompts are programs; this treats them as such.
- [src/colonyos/orchestrator.py]: Sequential-by-default eliminates a class of stochastic failures. Parallel merge conflicts require the model to understand both sides of a diff — a task LLMs are mediocre at. Making the system deterministic by default is the right call for autonomous operation.
- [src/colonyos/orchestrator.py]: Context window management is correct — completed tasks capped at 10 with omission notice, learnings injected, memory/injection context wired per-task.
- [src/colonyos/orchestrator.py]: Budget allocation (even division) is the simplest thing that works. Adaptive budgeting is V2.
- [src/colonyos/config.py]: Warning on parallel opt-in is informative without being blocking — correct severity level.
- [tests/test_sequential_implement.py]: 922 lines of tests for ~250 lines of implementation — excellent coverage. All 32 sequential tests pass. All prior tests pass (1 pre-existing xdist flake unrelated to this branch).

SYNTHESIS:
All 10 functional requirements are implemented, all 6 tasks are complete, 32 new tests pass, and all security fixes from prior rounds (selective staging, subprocess timeouts, commit message sanitization, audit logging) are properly in place. The architecture is fundamentally correct: sequential execution makes the system deterministic by ensuring each agent sees a clean, consistent filesystem rather than fighting nondeterministic merge conflicts. The prompt engineering is rigorous — redundant constraints at system and user prompt boundaries, context window management via trimming, and per-task memory injection. The only future improvement worth noting: passing structured summaries of prior task outputs (files created, APIs added) rather than just text descriptions would reduce re-reading overhead, but the current approach works because the agent can read the committed files directly. Ship it.