{
  "schema": "https://ai-atoms.com/schemas/skill-v1.json",
  "type": "skill",
  "id": "skill/performance-profiling",
  "version": "1.0.0",
  "name": "Performance Profiling",
  "description": "Performance profiling principles. Measurement, analysis, and optimization techniques.",
  "system_prompt_fragment": "# Performance Profiling\n\n> Measure, analyze, optimize - in that order.\n\n## 🔧 Runtime Scripts\n\n**Execute these for automated profiling:**\n\n| Script | Purpose | Usage |\n|--------|---------|-------|\n| `scripts/lighthouse_audit.py` | Lighthouse performance audit | `python scripts/lighthouse_audit.py https://example.com` |\n\n---\n\n## 1. Core Web Vitals\n\n### Targets\n\n| Metric | Good | Poor | Measures |\n|--------|------|------|----------|\n| **LCP** | < 2.5s | > 4.0s | Loading |\n| **INP** | < 200ms | > 500ms | Interactivity |\n| **CLS** | < 0.1 | > 0.25 | Stability |\n\n### When to Measure\n\n| Stage | Tool |\n|-------|------|\n| Development | Local Lighthouse |\n| CI/CD | Lighthouse CI |\n| Production | RUM (Real User Monitoring) |\n\n---\n\n## 2. Profiling Workflow\n\n### The 4-Step Process\n\n```\n1. BASELINE → Measure current state\n2. IDENTIFY → Find the bottleneck\n3. FIX → Make targeted change\n4. VALIDATE → Confirm improvement\n```\n\n### Profiling Tool Selection\n\n| Problem | Tool |\n|---------|------|\n| Page load | Lighthouse |\n| Bundle size | Bundle analyzer |\n| Runtime | DevTools Performance |\n| Memory | DevTools Memory |\n| Network | DevTools Network |\n\n---\n\n## 3. Bundle Analysis\n\n### What to Look For\n\n| Issue | Indicator |\n|-------|-----------|\n| Large dependencies | Top of bundle |\n| Duplicate code | Multiple chunks |\n| Unused code | Low coverage |\n| Missing splits | Single large chunk |\n\n### Optimization Actions\n\n| Finding | Action |\n|---------|--------|\n| Big library | Import specific modules |\n| Duplicate deps | Dedupe, update versions |\n| Route in main | Code split |\n| Unused exports | Tree shake |\n\n---\n\n## 4. Runtime Profiling\n\n### Performance Tab Analysis\n\n| Pattern | Meaning |\n|---------|---------|\n| Long tasks (>50ms) | UI blocking |\n| Many small tasks | Possible batching opportunity |\n| Layout/paint | Rendering bottleneck |\n| Script | JavaScript execution |\n\n### Memory Tab Analysis\n\n| Pattern | Meaning |\n|---------|---------|\n| Growing heap | Possible leak |\n| Large retained | Check references |\n| Detached DOM | Not cleaned up |\n\n---\n\n## 5. Common Bottlenecks\n\n### By Symptom\n\n| Symptom | Likely Cause |\n|---------|--------------|\n| Slow initial load | Large JS, render blocking |\n| Slow interactions | Heavy event handlers |\n| Jank during scroll | Layout thrashing |\n| Growing memory | Leaks, retained refs |\n\n---\n\n## 6. Quick Win Priorities\n\n| Priority | Action | Impact |\n|----------|--------|--------|\n| 1 | Enable compression | High |\n| 2 | Lazy load images | High |\n| 3 | Code split routes | High |\n| 4 | Cache static assets | Medium |\n| 5 | Optimize images | Medium |\n\n---\n\n## 7. Anti-Patterns\n\n| ❌ Don't | ✅ Do |\n|----------|-------|\n| Guess at problems | Profile first |\n| Micro-optimize | Fix biggest issue |\n| Optimize early | Optimize when needed |\n| Ignore real users | Use RUM data |\n\n---\n\n> **Remember:** The fastest code is code that doesn't run. Remove before optimizing.\n\n## When to Use\nThis skill is applicable to execute the workflow or actions described in the overview.",
  "applicable_domains": [
    "other"
  ],
  "category": "other",
  "invocation": [
    "/performance-profiling"
  ],
  "authored_by": "claudeskills.in community",
  "source_url": "https://claudeskills.in/skill/performance-profiling",
  "provenance": {
    "source": "claudeskills.in",
    "source_url": "https://claudeskills.in/skill/performance-profiling",
    "license": "unknown",
    "imported_at": "2026-09-03",
    "notes": "Aggregated by claudeskills.in from community GitHub lists."
  },
  "tags": [
    "claudeskills",
    "other"
  ],
  "lifecycle": "draft"
}