Performance and User Experience

A talk I gave at UX Fest 2013 at the offices of Fresh Tilled Soil in Boston, Massachusetts

1. RUM Distillation 101 UX Fest 2013 Jonathan Klein @jonathanklein Tuesday, October 1, 13
2. Some Etsy Stats • Handmade marketplace • 1.5 billion page views/month • Almost $1B in sales last year Tuesday, October 1, 13
3. Tuesday, October 1, 13
4. What We Focus On Tuesday, October 1, 13
5. Metrics We Care About Tuesday, October 1, 13
6. Metrics We Care About • Backend Load Time Tuesday, October 1, 13
7. Metrics We Care About • Backend Load Time • SEO, capacity, impacts first paint Tuesday, October 1, 13
8. Metrics We Care About • Backend Load Time • SEO, capacity, impacts first paint • Time to first paint Tuesday, October 1, 13
9. Metrics We Care About • Backend Load Time • SEO, capacity, impacts first paint • Time to first paint • Rendering Performance Tuesday, October 1, 13
10. Metrics We Care About • Backend Load Time • SEO, capacity, impacts first paint • Time to first paint • Rendering Performance Tuesday, October 1, 13
11. Time to First Paint Tuesday, October 1, 13
12. Tuesday, October 1, 13
13. Blocked By Tuesday, October 1, 13
14. Blocked By • Base HTML Page Tuesday, October 1, 13
15. Blocked By • Base HTML Page • CSS Tuesday, October 1, 13
16. Blocked By • Base HTML Page • CSS • JavaScript Tuesday, October 1, 13
17. Solutions Tuesday, October 1, 13
18. Solutions • Small CSS (can inline) Tuesday, October 1, 13
19. Solutions • Small CSS (can inline) • Defer JavaScript Tuesday, October 1, 13
20. Solutions • Small CSS (can inline) • Defer JavaScript • Fast backend Tuesday, October 1, 13
21. Solutions • Small CSS (can inline) • Defer JavaScript • Fast backend • CDN Tuesday, October 1, 13
22. Rendering Performance Tuesday, October 1, 13
23. 60 FPS Tuesday, October 1, 13
24. 16.6 ms Tuesday, October 1, 13
25. Tuesday, October 1, 13
26. Jank Tuesday, October 1, 13
27. http://jankfree.org/jank-busters-io-2013/template.html#15 Tuesday, October 1, 13
28. Why Do We Care? Tuesday, October 1, 13
29. Facebook artificially slowed down frame rate on iOS and Android to 30 FPS, and “engagement collapsed” - Shane O'Sullivan, Edge London 2013 Tuesday, October 1, 13
30. Etsy tested pre-fetching JS on our search results page, which caused jank as the JS finished downloading. All business metrics we monitored got much worse. - Me, right now Tuesday, October 1, 13
31. Solutions Tuesday, October 1, 13
32. Tuesday, October 1, 13
33. jankfree.org Tuesday, October 1, 13
34. Etsy Studies Tuesday, October 1, 13
35. Improved Performance Tuesday, October 1, 13
36. Improved Performance • Went from 4 sharded domains to two Tuesday, October 1, 13
37. Improved Performance • Went from 4 sharded domains to two • 500ms load time improvement on mobile Tuesday, October 1, 13
38. Improved Performance • Went from 4 sharded domains to two • 500ms load time improvement on mobile • 30-50ms on desktop Tuesday, October 1, 13
39. Improved Performance • Went from 4 sharded domains to two • 500ms load time improvement on mobile • 30-50ms on desktop • 0.27% increase in page views per visit Tuesday, October 1, 13
40. Increased Page Weight Tuesday, October 1, 13
41. Increased Page Weight • Added ~160k more bytes on mobile Tuesday, October 1, 13
42. Increased Page Weight • Added ~160k more bytes on mobile • 12% increase in bounce rate Tuesday, October 1, 13
43. Tradeoffs Tuesday, October 1, 13
44. Test Everything Tuesday, October 1, 13
45. Listen to the Customer Tuesday, October 1, 13
46. Faster is Better Tuesday, October 1, 13