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

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## Review Complete

**VERDICT: approve**

Here's the summary from my Principal Systems Engineer perspective:

### What's Good
- **Zero regressions**: All 1,687 existing tests pass. All 84 new TUI tests pass.
- **Clean architecture**: Frozen dataclasses over a janus queue for thread-safe event passing. The existing `ui_factory` injection point means zero changes to the orchestrator or agent code.
- **Proper isolation**: Textual is an optional dependency with import guards and graceful fallback errors.
- **Comprehensive test coverage**: 84 tests covering adapter queue contract, widgets, CLI integration, and app lifecycle.
- **Output sanitization**: All agent output sanitized at the adapter boundary before queueing — correct placement.

### Key Findings (non-blocking for v1)
1. **Queue consumer has no error handling** (Medium) — if any widget render throws, the consumer task dies silently and the TUI freezes with no indication. This is the #1 thing to fix before broader rollout.
2. **`_current_instance` singleton pattern** (Low) — fragile class-level mutable state; should pass queue directly into the callback.
3. **`on_mount` monkey-patching** (Low) — works today but brittle; initial prompt should be a constructor parameter.
4. **Redundant status bar renders** (Low) — spinner timer fires every 100ms with no no-op guard; multiple reactive attribute sets cascade renders.

The full review has been written to `cOS_reviews/reviews/principal_systems_engineer_google_stripe_caliber/20260323_round1_give_me_fucking_awesome_ux_that_is_a_fucking_amazing_experience_and_it_gets_peop.md`.