In every professional team that I've been on, nearly every change has gone through code review. Skipping code review is only done with a very good reason, like

In every professional team that I've been on, nearly every change has gone through code review. Skipping code review is only done with a very good reason, like if there's a time-sensitive change that you need to make and nobody is around to review it. Another reason to maybe skip code review is for prototype projects or internal tools where low-quality code is ok. Code review is not only a good way to spot bugs, it spreads knowledge and context throughout the team and makes sure everyone is consistent about both high-level and low-level coding practices. This is especially important when two people are writing code that will integrate with each other; normally each will look over the other's code. It also ensures that if something breaks, there are at least two people who might know how to fix it. Every software engineering context is different, but it seems like in most cases, it's irresponsible to ship code to users that has only been seen by one person. GitHub, Phabricator, and Gerrit are all good code review tools. I would recommend both using a tool like this and having a habit of talking through code changes in person.