Goodbye Code Review, Hello Pair Programming

presentation at Appdevcon 2020
https://appdevcon.nl/session/good-bye-code-review-hello-pair-programming

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Summary:

Code review is a good method to maintain a high code quality. However, there are some concerns that are introduced when this method is used too often.

For example, many members would request their code reviews to their lead engineers, which ends up having their lead engineers to shoulder more burden.

Besides, it takes up a lot of effort to communicate with the reviewer, and code reviews are often returned with many corrections, which is sometimes time-consuming. The solution to this problem is pair programming.

In this session, we would like to explain about pair programming, and share how we make use of it with TDD in our daily development.

Transcript

1. Goodbye Code Review, Hello Pair Programming Appdevcon 2020 Ryosuke Hiramatsu, Shizuna Ito
2. Ryosuke Hiramatsu iOS Engineer iOS Engineer Shizuna Ito
3. Our team • C2C e-commerce app • 6 iOS developers • released the app 8 months after formed • 5,000,000 DLs • developing with pair programming
4. What is pair programming? A development method in which
 two engineers write code jointly.
5. Working online with “Tuple” https://tuple.app
6. Two elements of pair programming TDD Pair Rotation
7. Pair Rotation • develop 1 feature per 1 pair 1 2 3
8. Pair Rotation • develop 1 feature per 1 pair • 1st day: A and B develop jointly 1 2 3
9. Pair Rotation • develop 1 feature per 1 pair • 1st day: A and B develop jointly • 2nd day: A remains and B rotates
 1 2 3
   
10. Pair Rotation • develop 1 feature per 1 pair • 1st day: A and B develop jointly • 2nd day: A remains and B rotates • 3rd day: A rotates 1 2 3
11. Pair Rotation • develop 1 feature per 1 pair • 1st day: A and B develop jointly • 2nd day: A remains and B rotates • 3rd day: A rotates Avoid relying on individual abilities. Share know-how with the team. 1 2 3
12. TDD RED GREEN Refactor
13. TDD • Failing test • Implementation code to pass the test • Refactor the code RED GREEN Refactor
14. TDD • Failing test • Implementation code to pass the test • Refactor the code Keep the rhythm of pair programming RED GREEN Refactor
15. DEMO
16. Appdevcon Sticker ¥3,000
17. Demo • Simple app making demo
18. Demo • Simple app making demo • No documents • test code = specification • concentrate on coding
19. Demo • Simple app making demo • No documents • test code = specification • concentrate on coding • Always teaching • Util class, shortcuts, and etc…
20. “Is development speed halved when working in pairs?”
21. Number of releases 0 10,000 2,500 5.000 7,500 1,173 1,185 2,829 8,221 Number of Releases Project A B C Our Project (Pair Programming)
22. Acceptance failure rate 0% 20% 5% 10% 15% Project A B C Our Project failure rate 11.3% 13.5% 8.6% 0.1% (Pair Programming)
23. Familiar with specifications “Did you become more familiar?” YES 81% 81% NO 19%
24. Recap of pair programming
25. Recap of pair programming • 1 code with 2 people

26. Recap of pair programming • 1 code with 2 people • more effective with pair-rotation and TDD
27. Recap of pair programming • 1 code with 2 people • more effective with pair-rotation and TDD • always develop with feedback

28. What I felt from experience • Always talk. A lot of communication • Communication brings respect and understanding • Essential for creativity of the team
 Respect High quality products Communication
29. Great Team High Quality Products
30. Question @himara2 @shizuna_it