---
id: T02
parent: S04
milestone: M013
provides: []
requires: []
affects: []
key_files: ["backend/pipeline/quality/optimizer.py", "backend/pipeline/quality/__main__.py", "backend/pipeline/quality/scorer.py", "backend/pipeline/quality/fixtures/sample_segments.json", "backend/pipeline/quality/fixtures/sample_topic_group.json", "backend/pipeline/quality/fixtures/sample_classifications.json"]
key_decisions: ["Fixed stage 5 fixture_keys to match existing fixture (moments not key_moments)", "Stage-specific user prompt building via _build_user_prompt() dispatch"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "All four task plan verification commands pass: optimizer imports ok, CLI imports ok, --help output works for stage 2, stage 6 is rejected. Additionally verified fixture loading for all stages 2-5 and that stage 1 is also rejected."
completed_at: 2026-04-01T09:24:39.815Z
blocker_discovered: false
---

# T02: Generalized OptimizationLoop to stages 2-5 with per-stage fixture validation, schema dispatch, and user prompt building; created stage 2-4 fixtures; removed stage-5 gate from CLI

> Generalized OptimizationLoop to stages 2-5 with per-stage fixture validation, schema dispatch, and user prompt building; created stage 2-4 fixtures; removed stage-5 gate from CLI

## What Happened
---
id: T02
parent: S04
milestone: M013
key_files:
  - backend/pipeline/quality/optimizer.py
  - backend/pipeline/quality/__main__.py
  - backend/pipeline/quality/scorer.py
  - backend/pipeline/quality/fixtures/sample_segments.json
  - backend/pipeline/quality/fixtures/sample_topic_group.json
  - backend/pipeline/quality/fixtures/sample_classifications.json
key_decisions:
  - Fixed stage 5 fixture_keys to match existing fixture (moments not key_moments)
  - Stage-specific user prompt building via _build_user_prompt() dispatch
duration: ""
verification_result: passed
completed_at: 2026-04-01T09:24:39.816Z
blocker_discovered: false
---

# T02: Generalized OptimizationLoop to stages 2-5 with per-stage fixture validation, schema dispatch, and user prompt building; created stage 2-4 fixtures; removed stage-5 gate from CLI

**Generalized OptimizationLoop to stages 2-5 with per-stage fixture validation, schema dispatch, and user prompt building; created stage 2-4 fixtures; removed stage-5 gate from CLI**

## What Happened

Rewrote optimizer.py to be fully stage-aware: constructor validates stage against STAGE_CONFIGS, _load_fixture() validates against config.fixture_keys, _score_variant() dispatches per-stage with stage-appropriate user prompts and schema parsing, run() uses config.prompt_file. Updated __main__.py to accept stages 2-5 and use stage-appropriate dimensions in leaderboard/results. Created three fixture files for stages 2-4. Fixed stage 5 fixture_keys mismatch from T01.

## Verification

All four task plan verification commands pass: optimizer imports ok, CLI imports ok, --help output works for stage 2, stage 6 is rejected. Additionally verified fixture loading for all stages 2-5 and that stage 1 is also rejected.

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `python -c "from pipeline.quality.optimizer import OptimizationLoop; print('optimizer ok')"` | 0 | ✅ pass | 500ms |
| 2 | `python -c "from pipeline.quality.__main__ import main; print('cli ok')"` | 0 | ✅ pass | 500ms |
| 3 | `python -m pipeline.quality optimize --stage 2 --iterations 1 --file ... --help 2>&1 | head -1` | 0 | ✅ pass | 500ms |
| 4 | `python -m pipeline.quality optimize --stage 6 --file x 2>&1 | grep -q 'stage'` | 0 | ✅ pass | 500ms |
| 5 | `Fixture validation for all stages 2-5` | 0 | ✅ pass | 500ms |


## Deviations

Fixed stage 5 fixture_keys from ['key_moments', 'creator_name'] to ['moments', 'creator_name'] — T01 config didn't match existing fixture.

## Known Issues

None.

## Files Created/Modified

- `backend/pipeline/quality/optimizer.py`
- `backend/pipeline/quality/__main__.py`
- `backend/pipeline/quality/scorer.py`
- `backend/pipeline/quality/fixtures/sample_segments.json`
- `backend/pipeline/quality/fixtures/sample_topic_group.json`
- `backend/pipeline/quality/fixtures/sample_classifications.json`


## Deviations
Fixed stage 5 fixture_keys from ['key_moments', 'creator_name'] to ['moments', 'creator_name'] — T01 config didn't match existing fixture.

## Known Issues
None.
