# Review by Principal Systems Engineer (Google/Stripe caliber) (Round 1)

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VERDICT: approve

FINDINGS:
- [src/colonyos/daemon/_watchdog.py]: `_get_daemon_module()` lazy-import pattern is clever and correctly preserves test mock targets, but adds indirection. Docstring explains the "why" well — acceptable.
- [src/colonyos/daemon/_resilience.py]: Cross-mixin dependency on `_HelpersMixin._record_runtime_incident` via `self` — implicit contract inherent to the mixin pattern. Not a blocker, but future extractors should be aware of the dependency graph between mixins.
- [src/colonyos/daemon/_helpers.py]: Bonus extraction beyond PRD scope (PRD specified 4 files, implementation has 5). Reasonable addition — 153 lines of pure-ish helpers cleanly separated.
- [tests/]: Zero test modifications — verified. 3 test failures are pre-existing on main (confirmed by running same tests on main branch).
- [src/colonyos/cli.py]: Zero modifications — verified. Import compatibility preserved.

SYNTHESIS:
This is a textbook conservative refactoring after 6 failed attempts. The implementation nails the key insight: mixins preserve `patch.object` mock targets while still decomposing the monolith. The `__init__.py` dropped from 2,655 to 1,975 lines (26% reduction) with zero test modifications — exactly the right trade-off. The `_get_daemon_module()` lazy-import pattern in `_watchdog.py` is the only non-obvious mechanism, and it's well-documented. The bonus `_HelpersMixin` extraction goes slightly beyond PRD scope but is low-risk (pure-ish functions) and additive. From a reliability perspective: if this breaks at 3am, the failure mode is identical to the monolith — all methods remain on `self`, all state access patterns are unchanged, and the MRO is deterministic. The commit sequence (5 atomic, sequential commits) means any regression is trivially bisectable. Ship it.
