In a new post to his blog today Hannes Magnusson talks about the benefits of doing a code review and getting your eyes on as much other people's code as possible (and a bit about a pleasant side effect of it).

Reading code is not only fun, its also a great way to exercise your brain - not to mention a fantastic way to discover new ways to solve problems. At work (we are hiring btw!), for example, I read pretty much every single commit (and merge requests, for that matter) - and I'm subscribed to several different OSS commit lists. I can't say I read every commit to PHP, I focus on the areas I care about, but I do skim over the rest - if only just to see when new features are added.

He talks about the various mailing lists that are around the PHP project (like the documentation, PEAR and PECL ones) and how many of the subscribers are cross-list, following along with multiple parts of the project.

Just the simple fact that I know people will be reading through my commits makes me think about what I am doing a bit more; "Is this really needed?", "Is there be a better way solving this?", "Could it potentially break other things?", "Is this actually correct?".. The people who review the commits often don't seem like the friendliest people in the world.. If there are issues with the commit; You will be told. No doubt about it.

What's the side effect I mentioned? Hannes' account credentials were hacked but, because of the code review process, a random commit from another developer was caught.