Dynamic Generation

Sergey Chernyshev talks about the reasons why we prefer generation+deployment workflow to calculating output in real time as users request information. We review the difference between generation and caches and why the former is more preferred strategy while latter is often misleading with it’s declared ease of implementation.

And in the end we look at the range of currently available solutions, from static generation to API-driven applications within JAMstack and introduce a new concept of “Dynamic Generators” and discuss how one can build a system that combines benefits of “generation” workflow and “dynamic” data to help expand fast User Experiences all the way across the full range of web application.

Transcript

1. Dynamic Generation January 24, 2019 @ JAMstack NYC Meetup Sergey Chernyshev
2. Sergey Chernyshev Principal Engineer @ Meetup January 24, 2019 @ JAMstack NYC Meetup • Care about
 UX speed • Organize
 NY Web Performance Meetup Group • Work on
 Web Platform team @ Meetup
3. • No PHP/Python/Ruby/ Java/ASP.Net/Node runtime! • No servers! • No databases! • Faster for users! Why Do We Generate?
4. Server-side Rendering Speed
5. Server-side Rendering Speed
6. Server-Side Rendered HTML • 1240ms @ Average • 3910ms @ 95%ile Static Resources • 483ms @ Average • 629ms @ 95%ile Generation is Faster • Bottleneck for the whole page • Much faster on average • Significantly less variable
7. • Carousell: -65% page load => +63% SEO, 3x ad clicks (2019) • Pinterest: -40% wait time => +15% SEO, +15% conversion (2017) • DoubleClick: 5s vs 19s on mobile => 2x ad revenue (2016) • Trainline: -300ms latency => +$11.5M / year revenue (2016) • Etsy: +160Kb => +12% bounce rate (2014) • Mozilla: -2.2s => +15.4% Downloads (2010) • Google: +400ms => -0.21% searches after experiment! (2009) • Netflix: +GZip => -43% Traffic cost (2008) • Amazon: +100ms => -1% revenue (2008) • Google: +500ms => -25% searches (2006) Stats @ WPOstats.com
8. Edge Cache vs. Generation
9. HTML Edge Cache
10. HTML Generation Workflow
11. • Renders on Read • Time To Live (TTL) • Stale for TTL/2 time • Cache hit ratio < 100% • Needs origin for misses • Renders on Write • Infinite TTL • Stale until updated • 100% offload Cache Generation
12. HTML Edge Cache without Invalidation
13. HTML Edge Cache with Invalidation
14. • API call • stale-while-revalidate • Surrogate keys for dependency tracking • Cache evictions • Shared CDN nodes • Long tail content • Deployment is invalidation • Serve stale while building • Incremental builds need dependency tracking • Storage & CPU cost $ • Each view is stored • Generates on write Invalidation ~ Generation
15. Static Generators
 with data in git Static with
 In-browser
 API calls Static Generators with API calls during build “Dynamic” Generators
16. Dynamic Generators
17. HTML Generation Workflow
18. Incremental Generation Workflow
19. • Maps changes to file names and edge cache keys • Sets renderer variables • auth / role • segmentation • language • Triggers incremental builds Dependency Manager
20. Dynamic Generation
21. Dynamic Generation Today
22. Dynamic Generation using GraphQL Subscriptions
23. • Know your real freshness / staleness requirements • Learn your existing data update cycle • Map data changes to outputs, list variations • Identify personalized vs. segmented content • Build your Dynamic Generator • Make your users happy! To Do
24. Thank You! Twitter: @sergeyche Sergey.Chernyshev@gmail.com SergeyChernyshev.com