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Performance profiling principles. Measurement, analysis, and optimization techniques.
Codex 또는 Claude로 설치 이 Prompt를 복사해 Codex, Claude 또는 다른 어시스턴트에 붙여 넣으면 Skill 페이지를 검토하고 설치를 진행할 수 있습니다.
SOC 직업 분류 기준
Gather relevant source files for a task, resolve their dependencies, and package everything into a structured context prompt.
Produce an architectural design and implementation plan based on task requirements, identifying scope, dependencies, impact, and a step-by-step rollout strategy.
Explore the codebase and export a structured context file (e.g., context.xml) for pasting into an external LLM like ChatGPT or Claude Web.
Trace execution paths from an error or bug report to find the root cause, gathering surrounding context (callers, imports, tests) along the way.
Analyze dependencies, callers, and coupling before refactoring, then produce a safe incremental refactoring plan.
Review recent code changes by gathering git diffs, identifying affected callers and tests, and analyzing for security, performance, and breaking changes.
| name | performance-profiling |
| description | Performance profiling principles. Measurement, analysis, and optimization techniques. |
| allowed-tools | Read, Glob, Grep, Bash |
Measure, analyze, optimize - in that order.
Execute these for automated profiling:
| Script | Purpose | Usage |
|---|---|---|
scripts/lighthouse_audit.py | Lighthouse performance audit | python scripts/lighthouse_audit.py https://example.com |
| Metric | Good | Poor | Measures |
|---|---|---|---|
| LCP | < 2.5s | > 4.0s | Loading |
| INP | < 200ms | > 500ms | Interactivity |
| CLS | < 0.1 | > 0.25 | Stability |
| Stage | Tool |
|---|---|
| Development | Local Lighthouse |
| CI/CD | Lighthouse CI |
| Production | RUM (Real User Monitoring) |
1. BASELINE → Measure current state
2. IDENTIFY → Find the bottleneck
3. FIX → Make targeted change
4. VALIDATE → Confirm improvement
| Problem | Tool |
|---|---|
| Page load | Lighthouse |
| Bundle size | Bundle analyzer |
| Runtime | DevTools Performance |
| Memory | DevTools Memory |
| Network | DevTools Network |
| Issue | Indicator |
|---|---|
| Large dependencies | Top of bundle |
| Duplicate code | Multiple chunks |
| Unused code | Low coverage |
| Missing splits | Single large chunk |
| Finding | Action |
|---|---|
| Big library | Import specific modules |
| Duplicate deps | Dedupe, update versions |
| Route in main | Code split |
| Unused exports | Tree shake |
| Pattern | Meaning |
|---|---|
| Long tasks (>50ms) | UI blocking |
| Many small tasks | Possible batching opportunity |
| Layout/paint | Rendering bottleneck |
| Script | JavaScript execution |
| Pattern | Meaning |
|---|---|
| Growing heap | Possible leak |
| Large retained | Check references |
| Detached DOM | Not cleaned up |
| Symptom | Likely Cause |
|---|---|
| Slow initial load | Large JS, render blocking |
| Slow interactions | Heavy event handlers |
| Jank during scroll | Layout thrashing |
| Growing memory | Leaks, retained refs |
| Priority | Action | Impact |
|---|---|---|
| 1 | Enable compression | High |
| 2 | Lazy load images | High |
| 3 | Code split routes | High |
| 4 | Cache static assets | Medium |
| 5 | Optimize images | Medium |
| ❌ Don't | ✅ Do |
|---|---|
| Guess at problems | Profile first |
| Micro-optimize | Fix biggest issue |
| Optimize early | Optimize when needed |
| Ignore real users | Use RUM data |
Remember: The fastest code is code that doesn't run. Remove before optimizing.