Chakde System Design Series - Optimization Techniques

Introduction

• Optimization is crucial for web development and in-demand for web applications
• Important for senior developer roles and interview questions
• Focus on network optimization in this episode, with asset, build, and monitoring optimization in future episodes

Types of Optimization Techniques

• Asset Optimization (JavaScript, CSS, images)
• Network Optimization
• Build Optimization
• Monitoring

Network Optimization Topics Covered

1. Lazy Loading
2. Loading JavaScript in Async Fashion
3. Content Visibility
4. Serving Critical CSS
5. Resource Hints
6. Caching
7. Client-Side Rendering
8. Server-Side Rendering
9. Compression Techniques
10. Avoiding Layout Shift and Repaint

Detailed Topics

Lazy Loading

• Delays resource loading to improve performance
• Use loading attribute in images and iframes:
  • lazy for non-critical resources
  • eager for critical resources
• Use Intersection Observer API for effective lazy loading

Loading JavaScript Asynchronously

• Add async attribute to script tag to allow downloading in parallel without blocking parsing
• Use defer attribute to download and execute script after HTML parsing is complete

Content Visibility

• Use CSS content-visibility: auto for lazy rendering
• Reduces rendering time significantly
• Only renders visible content in the viewport

Serving Critical CSS

• Split CSS into critical and non-critical parts
• Load critical CSS synchronously
• Load non-critical CSS using `media=