When designing the architecture for a web site, not everything you design is about the technology or the code structure. Perhaps one of the most important project decisions I think I implemented on “Project Shylock” was to implement mandatory code reviews before commit.
All code commits need to pass a build, run and basic sanity check.
The only times committed files won’t require a code review is for a basic copy text change (and maybe even then) or when development was performed as part of Paired Programming (and maybe even then) or for a binary file.
The benefits for code reviews are plastered all over the internet, but just to re-cap from my own personal experience.
Code Reviews produce the least buggy code
I’m sure there are some metrics out there that may prove TDD (Test Driven Development) makes for the least buggy code, but from my own anecdotal experience, nothing makes for more reliable code than having to go through it line-by-line in front of a peer and having to explain your decisions for each line of code.
Additionally, if you promote a development team where noone codes with ego (another topic!), then critical analysis of code structure and logic will flow naturally. It can be like getting a free refactor just before you commit your changes.
Code Reviews cross-pollenate knowledge
When I’m working on code in a team that doesn’t code review, the only time I know what everyone else is doing is during the daily scrum standup… and even then I only get a passing overview of their coding day.
When I’m on a team that is doing code review, I always know what 3 or 4 other people have been working on that week.. to the point that if they are away sick and a bug arises related to it, I generally feel comfortable to jump into the code and try my own hand at it.
I went away on vacation for 3 weeks and left my team on an honor system to keep code reviewing themselves. I was unpleasantly surprised to come back that they had been incredibly overloaded and in their work compression mode, they dropped their code reviews.
It’s an easy thing to do to say “Oh I’m too busy to do this”, but in the end, code reviews only take a few minutes most of the time, and can save HOURS of work… sometimes you don’t have to pay that tech debt until weeks later.. but it will be paid sooner or later.. trust me.