Experimental Refactoring with Go

Refactoring is essential to the software lifecycle. Can we make it safe enough to be a part of every company's CD workflow? In this talk attendees will learn how to: utilise multi-step deploys; tame feature flags; run multiple code paths concurrently in production without influencing users.

Transcript

1. Experimental Refactoring
2. FIND ME github.com/jelmersnoeck twitter.com/jelmersnoeck Jelmer Snoeck ABOUT ME - Tech Lead at manifold.co - Kubernetes - Terraform - Gopher since 2013 - Kubelist Contributor
3. $ tree - What and why? - Techniques & Tools - Zero Downtime Refactoring - Experimental Refactoring
4. Photo by Dan Gold on Unsplash Refactoring
5. Code refactoring is the process of restructuring existing computer code without changing its external behavior. Wikipedia
6. Refactoring is a controlled technique for improving the design of an existing code base. Martin Fowler
7. Refactoring is changing things, deploying it and hoping it didn’t break anything else. Most Developers
8. Photo by Emily Morter on Unsplash Why
9. Photo by Alfons Morales on Unsplash Readability
10. Photo by Anton Darius on Unsplash Code smells
11. Code smells - Duplication - Feature envy - Large methods - Dead code - …
12. Photo by Glen Carrie on Unsplash Bugs
13. Product Changes Photo by Chris Lawton on Unsplash Product changes
14. Product changes - New features - Modify existing features - …
15. Photo by Nainoa Shizuru on Unsplash Performance + scalability
16. Performance - Change of underlying package - Change of underlying algorithm - …
17. Scalability - Userbase growth (100 users to 100m users) - Team growth (10 developers to 500 developers) - …
18. Photo by Anoir Chafik on Unsplash
19. Techniques Photo by Uriel Soberanes on Unsplash
20. Techniques - Interface Abstraction - Type Aliasing (Go 1.9+) - Nil Objects - …
21. Interfaces (Abstraction) Photo by Rene Böhmer on Unsplash
27. Photo by Kipras Štreimikis on Unsplash Type Aliasing
33. Photo by Aaron Burden on Unsplash Nil Objects
41. Photo by Philip Swinburn on Unsplash Tools
42. Detection Tools - CodeCov - Linting - …
43. CodeCov Photo by Samuel Zeller on Unsplash
49. Linting Photo by Terri Bleeker on Unsplash
53. Refactoring Tools - Tests - Security that it still works - Gotests - Benchmarks - go test -bench=. - IDE - Extract methods - Find duplication easily
54. gotests Photo by rawpixel on Unsplash
59. go test -bench=. Photo by Ashley Baxter on Unsplash
64. Photo by Mark Hessling on Unsplash
65. Photo by Jyotirmoy Gupta on Unsplash
66. Photo by Marcus Benedix on Unsplash
67. Zero Downtime Refactoring Photo by Masaaki Komori on Unsplash
68. Multi Step Changes Photo by Jake Hills on Unsplash
76. Photo by Jane Carmona on Unsplash Feature Flags
78. Why use Feature Toggles? - Early Access to Features - Incremental roll outs to test hypothesis - Calendar Events (Mother’s day, Launches, …) - …
82. Metrics Photo by Carlos Muza on Unsplash
84. Experimental Refactoring Photo by chuttersnap on Unsplash
87. Photo by chuttersnap on Unsplash
102. @jelmersnoeck manifold.co Thanks!
103. Reading list - https://speakerdeck.com/campoy/understanding-nil - https://talks.golang.org/2016/refactor.article - https://dave.cheney.net/2013/06/30/how-to-write-benchmarks-in-go - https://github.com/cweill/gotests - https://github.com/github/scientist - https://github.com/jelmersnoeck/experiment - http://featureflags.io/ - https://github.com/launchdarkly/go-client - https://github.com/checkr/flagr