# Performance Review Report

**Branch**: feat/166-167-dashboard-cleanup -> main
**Date**: 2026-05-14

## Issues in Your Changes (BLOCKING)

No CRITICAL or HIGH performance issues found.

## Issues in Code You Touched (Should Fix)

No issues found.

## Pre-existing Issues (Not Blocking)

No CRITICAL pre-existing performance issues found.

## Suggestions (Lower Confidence)

- **Linear scan in detailEntityStatus useMemo** - `src/cli/dashboard/app.tsx:148-157` (Confidence: 65%) -- The `detailEntityStatus` useMemo calls `data?.schedules.find()` and `data?.loops.find()` on every recomputation. These arrays are bounded by `FETCH_LIMIT` and the find runs at most once per data poll (1-2s cadence), so the impact is negligible. If entity counts ever grew large, a Map-based lookup keyed by ID would be O(1) instead of O(n). Not actionable at current scale.

- **Duplicate linear scan in handlePauseResume** - `src/cli/dashboard/keyboard/handle-detail-keys.ts:112-119` (Confidence: 60%) -- The `handlePauseResume` handler repeats the same `.find()` pattern as `detailEntityStatus` in app.tsx. This runs only on a `p` keypress (user-initiated, infrequent), so the overhead is immaterial. The duplication is architectural (keyboard handler reads from dataRef, app component reads from data prop) and justified by the separation of concerns.

- **Removed workspace poll interval is a performance win** - `src/cli/dashboard/use-dashboard-data.ts:58-61` (Confidence: 95%) -- Removing the 750ms workspace poll interval eliminates a faster-than-main polling cadence. The remaining intervals (main: 1000ms, detail: 2000ms) reduce DB pressure. This is a positive performance change, not an issue. Noted for completeness.

## Summary

| Category | CRITICAL | HIGH | MEDIUM | LOW |
|----------|----------|------|--------|-----|
| Blocking | 0 | 0 | 0 | 0 |
| Should Fix | 0 | 0 | 0 | 0 |
| Pre-existing | 0 | 0 | 0 | 0 |

**Performance Score**: 9/10
**Recommendation**: APPROVED

## Analysis Notes

This PR is overwhelmingly a deletion PR (~2,800 lines removed, ~750 added). From a performance perspective, the changes are net positive:

1. **Workspace view removal eliminates the 750ms poll interval** -- The most aggressive polling cadence in the dashboard is gone. The remaining main (1s) and detail (2s) intervals are more conservative, reducing SQLite query load.

2. **Removed fetchWorkspaceExtras** -- This function performed parallel fetches (`getOrchestratorChildren` + `sumByOrchestrationId`) every 750ms. Its removal eliminates two recurring DB queries per workspace poll cycle.

3. **Removed workspace streaming infrastructure** -- The `childTaskIds`, `childTaskStatuses`, and multi-task output streaming arrays that fed the workspace grid are gone. The output stream hook now only handles a single detail-view task ID at a time, which is simpler and cheaper.

4. **useMemo for detailStreamTaskId** -- Converting the inline function `resolveDetailStreamTaskId()` to a `useMemo` (lines 108-115) prevents unnecessary recalculation on every render. The dependencies (`view`, `nav.orchestrationChildSelectedTaskId`, `outputRepository`) are stable across most renders.

5. **useMemo for detailEntityStatus** -- New computation (lines 148-157) is properly memoized with correct dependencies (`view`, `data?.schedules`, `data?.loops`). The linear `.find()` is negligible at current `FETCH_LIMIT` scale.

6. **Removed DashboardState.workspaceNav** -- Eliminating the `workspaceNav` field from reducer state removes per-render spread cost for workspace state that no longer exists. The reducer action set is smaller (2 fewer action types), making exhaustive switch cheaper.

7. **Removed computeWorkspaceLayout** -- Layout computation for the grid (column/row math, panel sizing) no longer runs on every render cycle. Only `computeMetricsLayout` remains.

No N+1 queries, memory leaks, blocking I/O, unbounded caches, or algorithmic complexity issues were introduced. The new `pauseOrResumeEntity` function is a simple switch dispatch with async service calls -- no performance concerns.
