This document outlines the key elements and benefits of code reviews in software development, emphasizing their role in improving code quality and fostering knowledge sharing among team members. It provides a checklist for evaluating code during reviews and discusses best practices for both giving and receiving feedback. The document concludes that while code reviews may slow down immediate progress, they ultimately enhance team efficiency and development standards.

1. THE ANATOMY OF A CODETHE ANATOMY OF A CODE
REVIEWREVIEW
GUILHERME GARNIERGUILHERME GARNIER

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4. A TRADITIONAL CI PIPELINEA TRADITIONAL CI PIPELINE

5. ADDING CODE REVIEWADDING CODE REVIEW

6. WHAT'S A CODE REVIEW?WHAT'S A CODE REVIEW?
A tool to:
improve code quality
share knowledge about the project
share knowledge about technologies, libraries, etc

7. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

8. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

9. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

10. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

11. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

12. CODE REVIEW WORKFLOWCODE REVIEW WORKFLOW

13. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST

14. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?

15. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?
Is it bug free?

16. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?
Is it bug free?
Is it expressive?

17. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?
Is it bug free?
Is it expressive?
Is it scalable?

18. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?
Is it bug free?
Is it expressive?
Is it scalable?
Does it follow the projects conventions and standards?

19. CODE REVIEW CHECKLISTCODE REVIEW CHECKLIST
Does the code do what it’s supposed to do?
Is it bug free?
Is it expressive?
Is it scalable?
Does it follow the projects conventions and standards?
Is it well tested? Does it handle corner cases?

20. BENEFITSBENEFITS
to the code author
to the reviewer
to the team

21. BENEFITS TO THE CODE AUTHORBENEFITS TO THE CODE AUTHOR

22. BENEFITS TO THE CODE AUTHORBENEFITS TO THE CODE AUTHOR
Learn about the project

23. BENEFITS TO THE CODE AUTHORBENEFITS TO THE CODE AUTHOR
Learn about the project
Learn about the technologies involved

24. BENEFITS TO THE CODE AUTHORBENEFITS TO THE CODE AUTHOR
Learn about the project
Learn about the technologies involved
Learn other ways to solve problems

25. BENEFITS TO THE CODE AUTHORBENEFITS TO THE CODE AUTHOR
Learn about the project
Learn about the technologies involved
Learn other ways to solve problems
Learn to accept critics

26. BENEFITS TO THE REVIEWERBENEFITS TO THE REVIEWER

27. BENEFITS TO THE REVIEWERBENEFITS TO THE REVIEWER
Learn about the changes

28. BENEFITS TO THE REVIEWERBENEFITS TO THE REVIEWER
Learn about the changes
Learn about the project

29. BENEFITS TO THE REVIEWERBENEFITS TO THE REVIEWER
Learn about the changes
Learn about the project
Learn about the technologies involved

30. BENEFITS TO THE REVIEWERBENEFITS TO THE REVIEWER
Learn about the changes
Learn about the project
Learn about the technologies involved
Develop a critical view of someone else's code

31. BENEFITS TO THE TEAMBENEFITS TO THE TEAM

32. BENEFITS TO THE TEAMBENEFITS TO THE TEAM
Shared code ownership

33. BENEFITS TO THE TEAMBENEFITS TO THE TEAM
Shared code ownership
Helps keeping standards

34. STARTING CODE REVIEWSSTARTING CODE REVIEWS

35. EACH PR SHOULD BE A COHESIVE UNITYEACH PR SHOULD BE A COHESIVE UNITY
easier to get context
easier to revert, if needed

36. READABILITY IS VERY IMPORTANTREADABILITY IS VERY IMPORTANT
make you code/test/docs as clear as possible
add context do your PR description (images, link to issues)

37. MAKE PRS AS SMALL AS POSSIBLEMAKE PRS AS SMALL AS POSSIBLE

38. RECEIVING CODE REVIEWSRECEIVING CODE REVIEWS

39. Be humble and thankful
Start discussions when needed

40. REVIEWING CODE REVIEWSREVIEWING CODE REVIEWS

41. TAKE TIME TO REVIEW, DON'T RUSHTAKE TIME TO REVIEW, DON'T RUSH

42. WATCH FOR DETAILSWATCH FOR DETAILS

43. DON'T BE LIMITED TO CRITICSDON'T BE LIMITED TO CRITICS
RECOGNIZE GOOD DECISIONSRECOGNIZE GOOD DECISIONS

45. IN CASE OF DOUBT, ASKIN CASE OF DOUBT, ASK

46. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS

47. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS
Won’t this slow me down?

48. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS
Won’t this slow me down?
How to handle large pull requests?

49. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS
Won’t this slow me down?
How to handle large pull requests?
How many reviewers do I need?

50. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS
Won’t this slow me down?
How to handle large pull requests?
How many reviewers do I need?
Do I need code reviews if I pair program?

51. COMMON PROBLEMS ANDCOMMON PROBLEMS AND
CONCERNSCONCERNS
Won’t this slow me down?
How to handle large pull requests?
How many reviewers do I need?
Do I need code reviews if I pair program?
When not to use code reviews?

52. CONCLUSIONSCONCLUSIONS

53. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term

54. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term
but faster in the long term

55. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term
but faster in the long term
It helps onboarding new people

56. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term
but faster in the long term
It helps onboarding new people
It helps sharing knowledge

57. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term
but faster in the long term
It helps onboarding new people
It helps sharing knowledge
It helps sharing code ownership

58. CONCLUSIONSCONCLUSIONS
Code reviews can make you slower in the short term
but faster in the long term
It helps onboarding new people
It helps sharing knowledge
It helps sharing code ownership
Reviewing code is also part of your job

59. LINKSLINKS
The anatomy of a code review:
TDC SP 2019 - Decodi cando o code review:
Google's Code Review Developer Guide:
Lessons From Google: How Code Reviews Build Company Culture:
Why junior devs should review seniors’ commits:
Anatomy Of A Code Review:
https://blog.guilhermegarnier.com/2018/05/the-
anatomy-of-a-code-review/
https://speakerdeck.com/elainenaomi/tdc-sp-2019-decodi cando-o-code-review
https://google.github.io/eng-
practices/review/
https://blog.fullstory.com/what-we-learned-from-google-code-reviews-arent-just-for-
catching-bugs/
https://pagefault.blog/2018/04/08/why-junior-devs-should-review-seniors-commits/
https://speakerdeck.com/asendecka/anatomy-of-a-
code-review

60. THANK YOU!THANK YOU!
Slides:
https://blog.guilhermegarnier.com
@gpgarnier
https://blog.guilhermegarnier.com/talk-code-review/