Migrating any codebase can be a daunting task. Where do you start? At Netflix we recently overhauled our entire codebase for the website to React and Node.js. Our goal was to migrate to a new codebase to iterate at a faster pace, but during migration we didn’t want to slow down innovation on new features. Along the way we learned how to improve the process and make sure we didn’t negatively impact the user experience. I'll be sharing a few tips and learnings to help make your next migration easier and more effective.

1. Migrating a large
codebase to Node &
React
Ryan Burgess
@burgessdryan

2. What is your reaction to
migrating to a new codebase?

4. Once the migration starts
it can be daunting

6. It doesn’t need to be
that frustrating

7. Who am I?

8. Software Engineer Manager at Netflix
@burgessdryan

11. Why migrate to a new codebase?
Why React & Node?
How did we tackle the migration at
Netflix?
What lessons did we learn?

12. Why migrate to a
new codebase?

13. The ability to innovate faster

14. Simplify & separate concerns

15. Developer productivity

16. Why Node.js?

17. Our UI team is familiar with JavaScript

18. Less context switching

19. Great tooling in the Node.js ecosystem

20. Allows for universal rendering of
UI components

21. Makes development faster
and increases productivity

22. We use Restify at Netflix
Lightweight
Absolute control over interactions with HTTP
Automatic DTrace support
https://github.com/restify/node-restify

23. Why React.js?

24. Why not any of these other frameworks?

25. React supports universal rendering

26. Lightweight

27. Performance / Virtual DOM

28. Unified our markup with
corresponding view logic

30. Developer happiness

31. A solid community

32. How we tackled the
migration at Netflix

33. Decouple design changes from
architecture changes

34. Don’t try to migrate all at once,
tackle in sections

35. Allows for flexibility and
ability to learn

36. Allowed us to pivot
Before leveraging React we used Dust.js
https://github.com/linkedin/dustjs

37. Plan to support two codebases

38. Leverage metrics
• Atlas metrics
• A/B test metrics

39. Atlas metrics

40. Atlas metrics

41. A/B test
vs

42. A/A test
vs

43. Metric cycle
Push to production
Check metricsInvestigate / Iterate

44. What lessons did
we learn?

45. Estimating a migration is hard

46. Choose a technology that works
for you and your team

47. Migrate in sections, not all at once

48. Design changes can impact
your metrics

49. Use metrics whenever possible

51. Thank you!
@burgessdryan