Name: Code Review Is NOT For Catching Bugs
Uploaded: 2022-04-05
Duration: 2 min 38 s
Description: Junior engineers often think that code review is about identifying and fixing bugs before they hit production

Code Review Is NOT For Catching Bugs

Junior engineers often think that code review is about identifying and fixing bugs before they hit production. This is **not** the primary benefit of a healthy code review culture. Instead, code review is critical to promote collaboration and knowledge sharing among team members.

Engineers can learn from each other's code and improve their own coding skills by seeing how their teammates approach problems. For engineers, leaving comments (or memes) on code is an ideal avenue to build culture and socialize. 

Focusing solely on finding bugs during code review can be counterproductive. If you're only looking for bugs, you may miss other important aspects of the code, such as maintainability, readability, and performance. 

Finally, bugs are often better caught through automated testing or other processes -- humans are not very good at this!

Related resources: 
- [Noob Software Engineer vs. Pro Software Engineer](https://www.jointaro.com/lesson/fTnWHqkYCPuaGa9FqaDf/noob-software-engineer-vs-pro-software-engineer/)
- [Use Code Review Feedback For Hypergrowth - Meta Prodigy Engineer Story](https://www.jointaro.com/lesson/aBRgdYpUfnUpoyWG4qZC/use-code-review-feedback-for-hypergrowth-meta-prodigy-engineer-story/)
- [How To Write Better Code Faster As A Software Engineer (Masterclass)](https://www.jointaro.com/lesson/iYpRj8XfyzCSaTYnce3y/masterclass-how-to-write-better-code-faster-as-a-software-engineer/)

Junior engineers often think that code review is about identifying and fixing bugs before they hit production

Code review is one of the most common and powerful ways for software engineers to learn. On top of increasing code quality, it builds engineering culture within a team.

Code review can catch coding mistakes and design flaws before the code reaches production

A good code review process is needed to catch bugs, increase maintainability, and guarantee a high velocity future contributors.

Code review ensures high quality software that is maintainable for the lifetime of the code

This collection represents the best of what Taro has to offer, personally curated by Alex and Rahul. If you're short on time, go through the content here.

[Masterclass] How To Do Amazing Code Review

Code review is one of the most effective ways to learn as a software engineer, especially for those earlier-in-career. Unfortunately, way too many engineering teams get it wrong with slow review speed and low quality comments.

There is a mountain of information in this presentation, so here's our 5 favorite points (in no particular order):
- **Code review is NOT for catching bugs** - Of course, if you find a bug in a PR (pull request), you should call it out, but that's not the primary purpose of code review. The core benefit of code review is to build up engineering culture, propagating best practices amongst the team and growing newer and more junior engineers.
- **Add deep context to your PRs** - Explain what your pull request does and the reasoning behind your approach. Also, *include a test plan.* A test plan is a demo showcasing what your code changes do; try to make it a video/gif, which is especially powerful if you work on front-end (Android/iOS/web). If you can't do a video, try attaching a screenshot or a set of commands to run tests.
- **One diff, one thesis** - Every PR should be focused and atomic: Don't jam the entire new feature you just coded up in a single 1,000+ line PR. Huge commits are hard to review, and your teammates will hate you for it. For the vast majority of cases, you can break down your PRs to 25-250 lines of code.
- **Read others' code reviews** - Similar to so many other things in tech, stand on the shoulders of giants where you can. With code review, this means looking at how senior+ engineers on your team comment on reviews. Try to find patterns in the issues they're finding and incorporate it into how you review code. Revisions that have been rejected with changes requested are a gold mine for this learning.
- **Code review MUST be fast** - When we say fast, we mean that feedback should arrive in <24 hours. What a lot of engineers don't realize is that code review delay is multiplicative: Sometimes commit will need 3-5 revisions before they're able to be merged. If turnaround is 2+ days, this can easily lead to commits taking weeks to land, which is far too slow.

A lot of the terminology in this video is Meta specific. If you're more used to GitHub:
- Diff review = Pull request
- Diff = Commit

Related resources:
- ["How to give better code reviews without full business context?"](https://www.jointaro.com/question/vio35mw1SYWM8AYojB2w/how-to-give-better-code-reviews-without-full-business-context/)
- ["How to review code in another language/ from another team?"](https://www.jointaro.com/question/B79W3aWc8xMB8cCULFdJ/how-to-review-code-in-another-language-from-another-team/)
- [Presentation Slides](https://docs.google.com/presentation/d/1koyIR9K_CtESD7Vnh3GQOE-svFW-ngrQeEAduSAoH0w/edit)