| name | plan-perf-audit |
| description | Measure-don't-guess performance audit across web, mobile, backend, and data layers — produces burndown and optimization plan with no fixes in this pass. No fabricated metrics; every issue needs a measured baseline or [NEEDS PROFILING]. Research-backed proposals for React (code-split, memo, react-window, startTransition), RN (Hermes, JSI, <2s cold start), data N+1/index work with EXPLAIN, and prevention via Lighthouse CI budgets + RUM. Mobile thresholds stricter than web CWV. Use when asked to "performance audit plan", "perf burndown", "measure before optimize", "bundle size audit", "LCP slow", "N+1 audit plan", "plan performance improvements", or "Core Web Vitals audit".
|
| license | MIT |
Performance Audit + Optimization Plan
Role: Senior performance engineer (web + mobile + backend/data).
Task: Profile the app, find performance issues across layers, plan fixes. Measure, don't
guess. Audit & plan only — do not optimize in this pass.
This skill vs neighbors
| Skill | Does |
|---|
| plan-perf-audit (this) | Plan with measured baselines |
audit-performance | Audit + may optimize |
audit-bundle-size | JS bundle focus + reduction |
backend-db-performance | Query/index fixes (execution) |
mobile-rn-performance | RN perf fixes (execution) |
Loop: see docs/PLAN-LOOPS.md — after plan-test-coverage, parallel with plan-security-audit, before plan-docs-sync
⛔ Preservation Contract
Read references/preservation-contract.md. Acknowledge in output #1.
Hardest guardrail: no fix proposed without a measured baseline (or explicit [NEEDS PROFILING]).
References
| File | Contents |
|---|
references/audit-scope.md | Layers, methodology, measurement, research fixes |
references/output-templates.md | Baselines, burndown, phased plan |
Phase flow
1. Fingerprint stack (web/RN/API/Supabase)
2. Measure baselines per layer (no guessing)
3. Trace hot paths
4. Per-layer issue inventory
5. Burndown + phased optimization plan
6. Guardrails (budgets, Lighthouse CI, RUM)
7. Research citations
Optional browser: Lighthouse via playwright-cli. Read protocol-browser-anti-stall first.
Phase 1 — Measure first
Establish baselines before any fix proposal:
| Layer | Tools |
|---|
| Web CWV | Lighthouse, web-vitals, RUM/Sentry |
| Bundle | rollup-plugin-visualizer, @next/bundle-analyzer |
| RN | Metro bundle report, cold start profiler |
| API | Sentry transactions, server logs |
| DB | Supabase advisors, EXPLAIN ANALYZE, slow query logs |
Scope detail: references/audit-scope.md
Phase 2–4 — Hot paths + inventory
Prioritize highest-traffic screens, endpoints, queries. Tie each issue to path:line or query text.
Root-cause, not symptom. Quantify expected gain where possible.
Phase 5 — Burndown + plan
Template: references/output-templates.md
Phases: (1) P0 hot-path wins → (2) structural → (3) polish.
Prevention: performance budgets in CI, RUM for real users, re-measure after each fix.
Required output (in order)
- Preservation-contract acknowledgment
- Measured baselines per layer
- Per-layer issue inventory
- Burndown table (measured current + target + risk)
- Optimization + enhancement plan, phased
- Guardrails/tooling
- Research notes + citations
- Open questions /
[NEEDS PROFILING] list
Rules
- Plan only — do not optimize until approved.
- Measure, don't guess. No fabricated numbers.
- Optimizations preserve behavior + output.
- Re-measure after fixes; keep before/after.
