# Performance

> Performance review of code changes or a hot path. Use when the user asks about slowness, optimization, N+1, bundle size, or scalability. Complements review pass 2. Not for micro-optimizing without evidence.

- Skill: `axidify/performance` (Agent Skill)
- Install (CLI): `npx skillmds@latest add axidify/performance`
- Raw SKILL.md: https://api.skillmd.com/api/skills/axidify/performance/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: Axidify (https://skillmd.com/u/axidify)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/axidify/performance

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# Performance review

For a full three-pass pre-commit review, start with **review**. This skill is **pass 2 only**, in depth.

Full checklist → [review/references/code-review-passes.md](../review/references/code-review-passes.md#pass-2-performance)

## Checklist

1. **Scope** — changed files or named hot path; **discover-project** if stack unclear
2. **Evidence** — prefer traces, slow queries, profiles, or repro metrics over guesses
3. **Request path** — blocking I/O, sync work, N+1, over-fetch, missing pagination
4. **Data layer** — missing filters/indexes (when visible); large payloads
5. **Caching** — redundant computation; cache invalidation risks
6. **Network** — excessive RPC/API calls; chatty clients
7. **UI** — redundant renders, heavy bundles, layout thrash (when frontend)
8. **Resources** — memory leaks; inefficient file/stream handling

## Per finding

| Field | Content |
|-------|---------|
| Severity | Critical / High / Medium / Low |
| File / location | Path + symbol |
| Problem | What is inefficient |
| Impact | Latency, throughput, cost, UX |
| Fix | Minimal change; measure if possible |

## Rules

- Do not optimize without a stated problem or measurement
- Do not trade readability for nanoseconds unless the user asked
- Implement fixes only when the user asked → **implement**
- For production incidents → **debug** first if cause is unknown

## Related skills

- **review** — three-pass pre-commit including quick performance scan
- **debug** — unknown slowness or regressions
- **implement** — apply approved optimizations
- **test** — benchmarks or load tests when the project has them