Performance Optimization and Progressive Web Enhancements

1. Welcome and Icebreaker:

• Icebreaker: “Have you ever left a website because it loaded too slowly? What happened?”

2. Outline the Session:

• Agenda:
  • Performance tuning (lazy loading, critical CSS)
  • Introduction to progressive web enhancements
• Learning Outcomes:
  • Optimize web performance
  • Apply progressive enhancement techniques
• Structure:
  • Theory, live coding, and hands-on practice
  • Interactive Q&A

3. Concept Explanation:

Performance optimization improves user experience and SEO. Techniques include lazy loading images, minimizing CSS, and using critical CSS. Progressive web enhancements add features for capable browsers without breaking basic functionality.

4. Live Coding Demonstration:

Example of lazy loading and critical CSS:

<style>
.critical {
  color: #333;
  font-weight: bold;
}
</style>
<img src="large-image.jpg" loading="lazy" alt="Lazy loaded image">

• Step-by-step:
  • Use loading="lazy" for images.
  • Inline critical CSS for above-the-fold content.
• Best Practice: Test performance with tools like Lighthouse.
• Common Pitfall: Loading all resources up front or not using progressive enhancement.

5. Tasks:

• Exercise:
  • Add a lazy-loaded image to your page.
  • Inline some critical CSS in your HTML.
  • Research one progressive enhancement (e.g., service workers) and summarize its benefit.