Performance Optimizer

This one gives Claude a structured approach to performance optimization based on the "measure first, optimize second" principle. It comes loaded with specific performance budgets including Core Web Vitals targets (LCP under 2.5s, FID under 100ms, CLS under 0.1) and covers the usual suspects: bundle size limits, database query optimization, caching strategies, and memory management. The skill includes sections on frontend, backend, and database performance, plus profiling tools and monitoring setup. If you're tired of premature optimization or need concrete benchmarks to argue against "just make it faster" requests, this gives you a systematic framework and actual numbers to work with.

GitHub stars: 33
last updated: Aug 21, 2026

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Install

$ npx -y skills add daffy0208/ai-dev-standards --skill 'Performance Optimizer' --agent claude-code

Installs into .claude/skills of the current project.

Files

Performance Optimizer

Make applications fast, scalable, and cost-efficient.

Core Principle

Measure first, optimize second. Don't guess at bottlenecks—profile, measure, then fix the slowest parts.

Performance Budget

Web Vitals (Target Metrics)

Core Web Vitals:
  Largest Contentful Paint (LCP): < 2.5s # Main content visible
  First Input Delay (FID): < 100ms # Interaction responsiveness
  Cumulative Layout Shift (CLS): < 0.1 # Visual stability

Additional Metrics:
  First Contentful Paint (FCP): < 1.8s # First content rendered
  Time to Interactive (TTI): < 3.8s # Fully interactive
  Total Blocking Time (TBT): < 200ms # Main thread blocked
  Speed Index: < 3.4s # Visual progress

Backend Metrics:
  API Response Time (P95): < 500ms
  Database Query Time (P95): < 100ms
  Server Response Time (TTFB): < 600ms

Phase 1: Profiling & Measurement

Goal: Identify actual bottlenecks, not perceived ones

Frontend Profiling

Chrome DevTools:

// 1. Performance tab → Record → Reload page
// 2. Analyze:
//    - Main thread activity
//    - Network waterfall
//    - JavaScript execution time
//    - Rendering time

SKILL.md on GitHub