Introducing Machine Learning to the JavaScript Toolchain

Websites are slow! Double-click shows that the average load time on a 3G network is 19 seconds! On top of that, on mobile devices, JavaScript compared to a JPG image with the same size may require x25 more processing time. How do you speed up your apps? Lazy-loading is here to help! By only loading the minimum amount of JavaScript during the initial page load you can improve the UX dramatically. However, this brings another set of questions - how to decide what to load lazily, and how to provide instant page load by mindfully prefetching the bundles, without draining the users’ mobile data plan? Machine learning is already playing an essential role in our day-to-day life, and it has the potential to assist in our development process for smaller, smarter, and faster JavaScript applications! In this talk, you'll see how you can create a machine learning model from a Google Analytics report. Later, by empowering static analysis techniques, we'll map this model to the lazy-loaded JavaScript chunks and apply predictive prefetching and data-driven bundling. In the last part of the presentation, you'll discover Guess.js which provides a sample implementation of these ideas.

Transcript

1. twitter.com/mgechev Introducing Machine Learning To The Javascript Toolchain twitter.com/mgechev github.com/mgechev blog.mgechev.com
2. twitter.com/mgechev twitter.com/mgechev github.com/mgechev
3. twitter.com/mgechev Evolution of the web UI Code-splitting Prefetching Guess.js Agenda
4. twitter.com/mgechev
5. twitter.com/mgechev
6. twitter.com/mgechev
7. twitter.com/mgechev https://medium.com/dev-channel/the-cost-of-javascript-84009f51e99e
8. twitter.com/mgechev lazy-loading
9. twitter.com/mgechev - Route-based - Component-based Lazy-loading strategies
10. twitter.com/mgechev Step 1: Open https://example.com/ Step 2: Determine JavaScript which is likely to be required Step 3: Download the chunks Step 4: Store chunks in browser cache Pre-fetching
11. twitter.com/mgechev How do we pick the priorities of the bundles to pre-fetch?
12. twitter.com/mgechev
13. twitter.com/mgechev Lazy-load everything!
14. twitter.com/mgechev Lazy-load everything! …and let tooling take care of the rest
15. twitter.com/mgechev
16. twitter.com/mgechev
17. twitter.com/mgechev Route-based splitting
18. twitter.com/mgechev $ npm run build # For Angular CLI $ serve -s dist
19. twitter.com/mgechev Let’s emulate *really* bad conditions
20. twitter.com/mgechev
21. twitter.com/mgechev
22. twitter.com/mgechev Let’s take a look at the GA graph
23. twitter.com/mgechev
24. twitter.com/mgechev
25. twitter.com/mgechev - Main & Settings in same chunk ‣ Update of the source code - Pre-fetch FAQ when the user is at Home Possible optimizations
26. twitter.com/mgechev
27. twitter.com/mgechev alpha
28. twitter.com/mgechev $ vim webpack.config.js
29. twitter.com/mgechev const { GuessPlugin } = require('guess-webpack'); // ... plugins: [ // ... new GuessPlugin({ GA: 'XXXXXX' }) ] // ...
30. twitter.com/mgechev
31. twitter.com/mgechev
32. twitter.com/mgechev How it works…
33. twitter.com/mgechev - guess-ga - guess-parser - guess-webpack Packages
34. twitter.com/mgechev guess-ga Fetching structured data from Google Analytics
35. twitter.com/mgechev guess-parser Gets metadata by statically analyzing our app
36. twitter.com/mgechev app-routing.module.ts pseudo code 
 const routes: Routes = [ { path: 'a/:id', loadChildren: './a.js' }, { path: 'b', loadChildren: './b.js' } ]; report
37. twitter.com/mgechev app-routing.module.ts pseudo code 
 const routes: Routes = [ { path: 'a/:id', loadChildren: './a.js' }, { path: 'b', loadChildren: './b.js' } ]; report
38. twitter.com/mgechev app-routing.module.ts pseudo code const module = 'settings.module.js'; const path = './settings'; const routes: Routes = [ { path: 'profile/:id', loadChildren: './profile/profile.module.js' }, { path: 'settings', loadChildren: path + '/' + module, } ];
39. twitter.com/mgechev app-routing.module.ts pseudo code const module = 'settings.module.js'; const path = './settings'; const routes: Routes = [ { path: 'profile/:id', loadChildren: './profile/profile.module.js' }, { path: 'settings', loadChildren: path + '/' + module, } ];
40. twitter.com/mgechev app-routing.module.ts pseudo code const module = 'settings.module.js'; const path = './settings'; const routes: Routes = [ { path: 'profile/:id', loadChildren: './profile/profile.module.js' }, { path: 'settings', loadChildren: path + '/' + module, } ];
41. twitter.com/mgechev guess-webpack Set of webpack plugins which automate the build
42. twitter.com/mgechev /a /a/a /a/b /b /b/a /
43. twitter.com/mgechev Markov Chain / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 /a /a/a /a/b /b /b/a /
44. twitter.com/mgechev /a /a/a /a/b /b /b/a / Activity: / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Probability threshold: 0.5
45. twitter.com/mgechev /a /a/a /a/b /b /b/a / Activity: / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Probability threshold: 0.5
46. twitter.com/mgechev /a /a/a /a/b /b /b/a / Activity: / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Probability threshold: 0.5
47. twitter.com/mgechev / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 /a /a/a /a/b /b /b/a / Activity: - Download b.bundle.js Probability threshold: 0.5
48. twitter.com/mgechev /a /a/a /a/b /b /b/a / Activity: - Download b.bundle.js / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Probability threshold: 0.5
49. twitter.com/mgechev /a /a/a /a/b /b /b/a / Activity: - Download b.bundle.js / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Probability threshold: 0.5
50. twitter.com/mgechev /a /a/a /a/b /b /b/a / / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Activity: - Download b.bundle.js - No action Probability threshold: 0.5
51. twitter.com/mgechev /a /a/a /a/b /b /b/a / / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Activity: - Download b.bundle.js - No action Probability threshold: 0.5
52. twitter.com/mgechev /a /a/a /a/b /b /b/a / / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Activity: - Download b.bundle.js - No action Probability threshold: 0.5
53. twitter.com/mgechev /a /a/a /a/b /b /b/a / / /a /a/:id /b /b/a / 0 0.3 0 0.7 0 /a 0 0 0.9 0.1 0 /a/:id 0 1 0 0 0 /b 0 0 0 0 1 /b/a 0 1 0 0 0 Activity: - Download b.bundle.js - No action - Download a.bundle.js Probability threshold: 0.5
54. twitter.com/mgechev
55. twitter.com/mgechev
56. twitter.com/mgechev
57. twitter.com/mgechev - Ahead-of-Time predictions - Collaboration with TF.js - Finer granular prefetching Future development
58. twitter.com/mgechev - https://mgv.io/dd-bundling - https://mgv.io/cost-of-js - https://mgv.io/predictive-fetching - https://mgv.io/guess References
59. Thank you! twitter.com/mgechev github.com/mgechev blog.mgechev.com