Performance Optimization

This guide documents our established patterns for optimizing performance, using real examples from our codebase.

Quick Decision Guide

Use this flowchart to determine the appropriate optimization strategy:

Key Decision Points:

• Data Loading: Server vs Client-side data fetching
• UI Type: Static vs Interactive components
• Asset Type: Images, Scripts, or Styles
• Loading Priority: Critical vs Non-critical

Common Pitfalls:

• Client-side data transforms
• Eager loading of below-fold content
• Missing image optimization
• Unoptimized bundle sizes

Optimization Strategies

Data Loading

Use server-side data loading and transformation whenever possible:

// Good: Server-side transform
---
const data = await fetchData();
const processed = transformOnServer(data);
---
<Component data={processed} />

// Avoid: Client-side transform
<Component
  data={data}
  client:load
  transform={transformOnClient}
/>

Component Loading

Strategic component hydration:

// Critical above-fold content
<Header client:load />

// Below-fold interactive content
<Comments client:visible />

// Non-critical features
<ShareButtons client:idle />

Asset Optimization

Image optimization with Imgix:

<ImgixImage
  src={src}
  width={800}
  height={600}
  sizes="(min-width: 1024px) 800px, 100vw"
/>

Bundle Optimization

Route-based code splitting:

pages/[slug].astro

const { Comment } = await import('../components/Comment');

Monitoring

Use performance monitoring to track:

1. Core Web Vitals

   • LCP (Largest Contentful Paint)
   • FID (First Input Delay)
   • CLS (Cumulative Layout Shift)

2. Custom Metrics

   • Component hydration timing
   • Data loading performance
   • Asset loading timing

Decision Checklist

When optimizing performance:

1. Data Strategy

   • Server-side transforms where possible
   • Appropriate loading patterns
   • Caching strategy defined
   • Error handling in place

2. Component Strategy

   • Correct hydration directive
   • Loading states implemented
   • Error boundaries set up
   • Bundle impact considered

3. Asset Strategy

   • Images optimized
   • Scripts properly loaded
   • Styles optimized
   • Resources prioritized

4. Monitoring Strategy

   • Core Web Vitals tracked
   • Custom metrics defined
   • Alerts configured
   • Regular review process