Feature Flag Use Cases You Haven't Heard About Yet

This is the deck I presented at LeadDev Berlin 2022 on November 4, 2022.

The second to last slide contains further reading and resources.

Transcript

1. © 2022 Split Software, Inc. Joy Ebertz Principal Engineer Feature Flag Use Cases You Haven't Heard About Yet
2. © 2022 Split Software, Inc. Agenda ▸ What are feature flags? ▸ Typical Use Cases ▸ Removing Dead Code ▸ Load/Stress Testing ▸ Evaluating Tech Costs ▸ Parity Testing
3. © 2022 Split Software, Inc. What Are Feature Flags?
4. © 2022 Split Software, Inc. Other Terms • Feature Toggle
5. © 2022 Split Software, Inc. Other Terms • Feature Toggle • Feature Flip
6. © 2022 Split Software, Inc. Other Terms • Feature Toggle • Feature Flip • Feature Switch
7. © 2022 Split Software, Inc. Other Terms • Feature Toggle • Feature Flip • Feature Switch • Conditional Feature
8. © 2022 Split Software, Inc. Other Terms • Feature Toggle • Feature Flip • Feature Switch • Conditional Feature • Split
9. © 2022 Split Software, Inc. Code Branch Controlled by GUI
10. © 2022 Split Software, Inc. Code Sample if (Treatments.ON .equals(_splitClient.getTreatment(orgId, Splits.MY_FEATURE.name()))) { // Do Something } else { // Do Something Else }
11. © 2022 Split Software, Inc.
12. © 2022 Split Software, Inc. Code Sample if (Treatments.ON .equals(_splitClient.getTreatment(orgId, Splits.MY_FEATURE.name()))) { // Do Something } else { // Do Something Else }
13. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features
14. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features • Production Testing
15. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features • Production Testing • A/B/C Testing
16. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features • Production Testing • A/B/C Testing • Custom Packages
17. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features • Production Testing • A/B/C Testing • Custom Packages • Temporary UI Customization
18. © 2022 Split Software, Inc. Typical Use-Cases • Releasing features • Production Testing • A/B/C Testing • Custom Packages • Temporary UI Customization
19. © 2022 Split Software, Inc. Releasing Features • Separating Deploy from Release • Canary/Ramped Release • Off Switch
20. © 2022 Split Software, Inc. What Are Some Advanced Use-Cases?
21. © 2022 Split Software, Inc. Remove Dead Code
22. © 2022 Split Software, Inc. Why is your code dead?
23. © 2022 Split Software, Inc. Method no longer referenced Why is your code dead?
24. © 2022 Split Software, Inc. Method no longer referenced Endpoint never called Why is your code dead?
25. © 2022 Split Software, Inc. Method no longer referenced Parameter never has certain values Endpoint never called Why is your code dead?
26. © 2022 Split Software, Inc. log.info(“CODE NOT DEAD UID: 12345”);
27. © 2022 Split Software, Inc.
28. © 2022 Split Software, Inc. private void logForCleanup(String orgId, String uid) { if (Treatments.ON .equals(_splitClient.getTreatment(orgId, Splits.CLEANUP.name()))) { String message = String.format(“CODE NOT DEAD UID: %s”, uid); log.info(message); } }
29. © 2022 Split Software, Inc. private void logForCleanup(String orgId, String uid) { if (Treatments.ON .equals(_splitClient.getTreatment(orgId, Splits.CLEANUP.name()))) { String message = String.format(“CODE NOT DEAD UID: %s”, uid); log.info(message); } } Turn on CLEANUP feature flag to 1%
30. © 2022 Split Software, Inc. 1. Roll out to 1%
31. © 2022 Split Software, Inc. 1. Roll out to 1% 2. Remove any log lines hit
32. © 2022 Split Software, Inc. 1. Roll out to 1% 2. Remove any log lines hit 3. Roll out to 5%
33. © 2022 Split Software, Inc. 1. Roll out to 1% 2. Remove any log lines hit 3. Roll out to 5% 4. Remove any log lines hit
34. © 2022 Split Software, Inc. 1. Roll out to 1% 2. Remove any log lines hit 3. Roll out to 5% 4. Remove any log lines hit 5. Roll out to 100% …
35. © 2022 Split Software, Inc. 1. Roll out to 1% 2. Remove any log lines hit 3. Roll out to 5% 4. Remove any log lines hit 5. Roll out to 100% 6. Remove any code that hasn’t been hit … …
36. © 2022 Split Software, Inc. Load & Stress Test
37. Requests Mirrored Traffic Feature Flag Check New System Old System
38. Requests Mirrored Traffic Feature Flag Check New System Old System Load Test
39. Requests Mirrored Traffic Feature Flag Check New System Old System Stress Test
40. © 2022 Split Software, Inc. Evaluate Tech Costs
41. © 2022 Split Software, Inc. Requests Mirrored Traffic Feature Flag Check New System Old System
42. © 2022 Split Software, Inc. Requests Mirrored Traffic Feature Flag Check New System Old System
43. © 2022 Split Software, Inc. Requests Mirrored Traffic Feature Flag Check New System Old System
44. © 2022 Split Software, Inc. Verify Parity
45. © 2022 Split Software, Inc. New System Feature Flag Parity Check Old System Requests
46. © 2022 Split Software, Inc. Feature Flag Parity Check Requests Old System New System
47. © 2022 Split Software, Inc. Feature Flag Parity Check Requests Old System New System
48. © 2022 Split Software, Inc. Feature Flag Parity Check Requests Old System New System
49. © 2022 Split Software, Inc. Feature Flag Parity Check Log if different Requests Old System New System
50. © 2022 Split Software, Inc. Feature Flag Parity Check Log if different Requests Old System New System
51. © 2022 Split Software, Inc. Recap ▸ What are feature flags? ▸ Typical Use Cases ▸ Removing Dead Code ▸ Load/Stress Testing ▸ Evaluating Tech Costs ▸ Parity Testing
52. © 2022 Split Software, Inc. Questions? • Come talk to me at the speaker tables • Email me: joy.ebertz@split.io • Scan the QR code to enter our raffle to win a prize!
53. © 2022 Split Software, Inc. Joy Ebertz @jkebertz Joy.Ebertz@split.io Thank You!
54. © 2022 Split Software, Inc. Further Reading • My blog on this topic: https://www.split.io/blog/5-advanced-feature- flag-uses/ • Some ways we use feature flags: https://www.split.io/blog/feature-flags-at-split/ • More about feature flags generally: https://martinfowler.com/articles/feature- toggles.html
55. © 2022 Split Software, Inc. Image Credits • Elephant by Dmitry Abramov on https://pixabay.com • Server by Mohamed Hassan from Pixabay • Logs Photo by Radek Grzybowski on Unsplash • Heartbeat by Clker-Free-Vector-Images from Pixabay • Zombie Photo by julien Tromeur on Unsplash • Typewriter from https://undraw.co/license • Flagging image owned by Split • All others are PowerPoint Icons