## PERFORMANCE GUIDE

### 1. Performance Philosophy

Performance isn't a luxury. It's a requirement. At ego.cx, every millisecond counts because every millisecond affects user experience, conversion, and search engine ranking.

**Our principles:**
- **Fast by default** — performance is designed, not patched
- **Measured and monitored** — you can't improve what you don't measure
- **Accessible** — performance is also inclusivity

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### 2. Key Metrics

| Metric | Target | Tool |
|--------|--------|------|
| **LCP** (Largest Contentful Paint) | < 2.5s | Lighthouse / Web Vitals |
| **FID** (First Input Delay) | < 100ms | Lighthouse / Web Vitals |
| **CLS** (Cumulative Layout Shift) | < 0.1 | Lighthouse / Web Vitals |
| **TTFB** (Time to First Byte) | < 200ms | Lighthouse / Web Vitals |
| **Total load time** | < 3s | PageSpeed Insights |
| **Page size** | < 2MB | DevTools / WebPageTest |

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### 3. Best Practices

#### 3.1. Images
- **Format:** WebP or AVIF (with JPEG/PNG fallback)
- **Compression:** optimized without quality loss
- **Size:** responsive (srcset)
- **Lazy loading:** native (`loading="lazy"`) + Intersection Observer for below‑fold images

#### 3.2. Code
- **Minify:** CSS, JS, HTML
- **Bundling:** group but don't over‑bundle
- **Tree shaking:** remove unused code
- **Code splitting:** load only what's needed

#### 3.3. Fonts
- **Asynchronous loading:** `font-display: swap`
- **Subset:** only the necessary characters
- **Preload:** for critical fonts

#### 3.4. Caching
- **CDN:** for static content delivery
- **Browser cache:** with `Cache-Control` headers
- **Service Worker:** for offline caching

#### 3.5. Third‑parties
- **Deferred loading:** third‑party scripts (analytics, videos)
- **Self‑hosted:** when possible
- **Light libraries:** avoid heavy dependencies

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### 4. Monitoring Tools

- **Lighthouse:** audit in development and production
- **PageSpeed Insights:** quick view from Google
- **Web Vitals:** real‑time monitoring (Chrome User Experience Report)
- **WebPageTest:** detailed analysis from multiple locations
- **Sentry:** error and performance monitoring

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### 5. Performance Checklist

**Before deployment:**
- [ ] Images optimized and in WebP/AVIF
- [ ] CSS and JS minified
- [ ] Lazy loading configured
- [ ] Fonts preloaded with `font-display: swap`
- [ ] Cache configured
- [ ] CDN active
- [ ] Third‑parties loaded deferred

**Post‑deployment:**
- [ ] Lighthouse > 90 in Performance
- [ ] Core Web Vitals within thresholds
- [ ] Load time < 3s
- [ ] Console errors minimized

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### 6. Continuous Improvement Plan

| Frequency | Action |
|-----------|--------|
| **Weekly** | Review Web Vitals metrics |
| **Monthly** | Lighthouse and PageSpeed audit |
| **Quarterly** | Dependency review and updates |
| **Annual** | Full performance and architecture audit |

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*Last updated: 2026-07-10*

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*— Fernando José Caicedo Albarello*  
*Founder, EgoCX*