Web performance

1. Web performance guides
2. Animation performance and frame rate
3. CSS and JavaScript animation performance
4. Critical rendering path
5. Performance fundamentals
6. Populating the page: how browsers work
7. Recommended Web Performance Timings: How long is too long?
8. Lazy loading
9. Navigation and resource timings
10. Optimizing startup performance
11. Performance budgets
12. Performance Monitoring: RUM vs. synthetic monitoring

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.