performance-profiling
Skill130 starsChanged 10 months agoMITView on GitHub
Performance profiling principles. Measurement, analysis, and optimization techniques.
Files
Performance Profiling
Measure, analyze, optimize - in that order.
🔧 Runtime Scripts
Execute these for automated profiling:
| Script | Purpose | Usage |
scripts/lighthouse_audit.py | Lighthouse performance audit | python scripts/lighthouse_audit.py https://example.com |
1. Core Web Vitals
Targets
| Metric | Good | Poor | Measures |
| LCP | < 2.5s | > 4.0s | Loading |
| INP | < 200ms | > 500ms | Interactivity |
| CLS | < 0.1 | > 0.25 | Stability |
When to Measure
| Stage | Tool |
| Development | Local Lighthouse |
| CI/CD | Lighthouse CI |
| Production | RUM (Real User Monitoring) |
2. Profiling Workflow
The 4-Step Process
1. BASELINE → Measure current state
2. IDENTIFY → Find the bottleneck
3. FIX → Make targeted change
4. VALIDATE → Confirm improvementProfiling Tool Selection
| Problem | Tool |
| Page load | Lighthouse |
| Bundle size | Bundle analyzer |
| Runtime | DevTools Performance |
| Memory | DevTools Memory |
| Network | DevTools Network |
3. Bundle Analysis
What to Look For
| Issue | Indicator |
| Large dependencies | Top of bundle |
| Duplicate code | Multiple chunks |
| Unused code | Low coverage |
| Missing splits | Single large chunk |
Optimization Actions
| Finding | Action |
| Big library | Import specific modules |
| Duplicate deps | Dedupe, update versions |
| Route in main | Code split |
| Unused exports | Tree shake |
4. Runtime Profiling
Performance Tab Analysis
| Pattern | Meaning |
| Long tasks (>50ms) | UI blocking |
| Many small tasks | Possible batching opportunity |
| Layout/paint | Rendering bottleneck |
| Script | JavaScript execution |
Memory Tab Analysis
| Pattern | Meaning |
| Growing heap | Possible leak |
| Large retained | Check references |
| Detached DOM | Not cleaned up |
5. Common Bottlenecks
By Symptom
| 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 |
6. Quick Win Priorities
| 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 |
7. Anti-Patterns
| ❌ 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.
Other versions23 projects use a version of this.
Word for word · 5
- VoDaiLocz/kilo-kit-mcp★ 26100% same
- xfstudio/skills★ 9100% same
- SKB3002/agenthub★ 4100% same
- ai4brands-design/claude-skills★ 2100% same
- sid-lakhani/agents-config★ 2100% same
Edited · 5
- vudovn/ag-kit★ 8.2k91% same
- vudovn/antigravity-kit★ 8.2k91% same
- soumatheusgomes/agentville★ 988% same
- Ghosteken/agent-harness★ 283% same
- jornalistainclusivo/jinc-skills★ 1100% same
Wrote their own version · 13
- LiberatedPixelCup/Universal-LPC-Spritesheet-Character-Generator★ 1.9ksame name
- conorluddy/xclaude-plugin★ 186same name
- HeshamFS/materials-simulation-skills★ 83same name
- nahid-sparktales/agent-dispatcher★ 59same name
- ChariereFiedler/ronce-racine★ 8same name
- pmarreck/llm_skills★ 2same name
- andr-ca/agentharness★ 1same name
- codecharmhq/claude-code-skills★ 1same name
- Bridev04/clauderail★ 0same name
- dhriyatinandu-bot/claude-skills★ 0same name
3 more not listed
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
Used alongsideProjects with it also use intelligent-routing and nextjs-react-expert.
Other files people use alongside this one.
Files found in the same public projects as a version of this one, more often than they turn up anywhere else. Each project counts once, large collections count for less, and this file's own repository is left out.
SKB3002Skillintelligent-routing
Automatic agent selection and intelligent task routing. Analyzes user requests and automatically selects the best specialist agent(s) without requiring explicit user mentions.
Also in 5 projects that use this
- SKB3002Skill
nextjs-react-expert
React and Next.js performance optimization from Vercel Engineering. Use when building React components, optimizing performance, eliminating waterfalls, reducing bundle size, reviewing code for performance issues, or implementing server/client-side optimizations.
Also in 3 projects that use this
In this repository45 other files it gives its agents.
- api-patternsSkill
- app-builderSkill
- templatesSkill
- architectureSkill
- bash-linuxSkill
- behavioral-modesSkill
- brainstormingSkill
- clean-codeSkill
- code-review-checklistSkill
- database-designSkill
- deployment-proceduresSkill
- documentation-templatesSkill
- frontend-designSkill
- 2d-gamesSkill
- 3d-gamesSkill
- game-artSkill
- game-audioSkill
- game-designSkill
- mobile-gamesSkill
- multiplayerSkill
- pc-gamesSkill
- game-developmentSkill
- vr-arSkill
- web-gamesSkill
- geo-fundamentalsSkill
- i18n-localizationSkill
- lint-and-validateSkill
- mcp-builderSkill
- mobile-designSkill
- nextjs-best-practicesSkill
- nodejs-best-practicesSkill
- parallel-agentsSkill
- plan-writingSkill
- powershell-windowsSkill
- python-patternsSkill
- react-patternsSkill
- red-team-tacticsSkill
- seo-fundamentalsSkill
- server-managementSkill
- systematic-debuggingSkill
- tailwind-patternsSkill
- tdd-workflowSkill
- testing-patternsSkill
- vulnerability-scannerSkill
- webapp-testingSkill
Does it work?
Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.
No reviews yet
People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.
- It worked
- Partly
- It didn't
Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.
Your trail
Files you open will collect here, so you can find them again.
Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.
Now do this for your own.
Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.