wasabeef/claude-code-cookbook/analyze-performance

User Experience Score: B+ (78/100)
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⏱️ Core Web Vitals
├─ LCP (Loading): 2.3s [Good] Target<2.5s ✅
├─ INP (Interaction): 95ms [Good] Target<200ms ✅
├─ CLS (Visual Stability): 0.08 [Good] Target<0.1 ✅
├─ FCP (First Paint): 1.8s [Good] Target<1.8s ✅
├─ TTFB (Server): 450ms [Needs Work] Target<200ms ⚠️
└─ TTI (Interactive): 3.5s [Needs Work] Target<3.8s ⚠️
 
📊 Perceived Speed
├─ Initial Load: 2.3s [Industry avg: 3.0s]
├─ Page Navigation: 1.1s [Industry avg: 1.5s]
├─ Search Results: 0.8s [Industry avg: 1.2s]
├─ Form Submission: 1.5s [Industry avg: 2.0s]
└─ Image Loading: Lazy loading implemented ✅
 
😊 User Satisfaction Prediction
├─ Bounce Rate: 12% (Industry avg: 20%)
├─ Completion Rate: 78% (Target: 85%)
├─ NPS Score: +24 (Industry avg: +15)
└─ Return Rate: 65% (Target: 70%)
 
📊 User Experience Impact
├─ 0.5s faster display → -7% bounce rate
├─ 5% bounce reduction → +15% session length
├─ Search improvement → +15% time on site
└─ Overall UX improvement: +25%
 
🎯 Expected Improvement Effects (Priority Order)
├─ [P0] TTFB improvement (CDN) → LCP -0.3s = +15% perceived speed
├─ [P1] JS bundle optimization → TTI -0.8s = -20% interactive time
├─ [P2] Image optimization (WebP) → -40% transfer = -25% load time
└─ [P3] Cache strategy → 50% faster repeat visits

# Comprehensive UX score analysis
find . -name "*.js" -o -name "*.ts" | xargs wc -l | sort -rn | head -10
"Calculate UX performance score and evaluate Core Web Vitals"
 
# Performance bottleneck detection
grep -r "for.*await\|forEach.*await" . --include="*.js"
"Detect async processing bottlenecks and analyze UX impact"
 
# User experience impact analysis
grep -r "addEventListener\|setInterval" . --include="*.js" | grep -v "removeEventListener\|clearInterval"
"Analyze performance impact on user experience"

# Bundle size and load time
npm ls --depth=0 && find ./public -name "*.js" -o -name "*.css" | xargs ls -lh
"Identify bundle size and asset optimization improvements"
 
# Database performance
grep -r "SELECT\|findAll\|query" . --include="*.js" | head -20
"Analyze database query optimization points"
 
# Dependency performance impact
npm outdated && npm audit
"Evaluate performance impact of outdated dependencies"

Improvement ROI = (Time Savings + Quality Improvement) ÷ Implementation Effort

# Profiling
node --prof app.js
clinic doctor -- node app.js
 
# Bundle analysis
npx webpack-bundle-analyzer
lighthouse --chrome-flags="--headless"

-- Query analysis
EXPLAIN ANALYZE SELECT ...
SHOW SLOW LOG;

# React performance
grep -r "useMemo\|useCallback" . --include="*.jsx"
 
# Resource analysis
find ./src -name "*.png" -o -name "*.jpg" | xargs ls -lh