Yes, we're absolutely doing code reviews for each PR. Should have mentioned it in the post. Our general policy is to have engineers merge their own PRs, but only after at least 1-2 people have reviewed them (and obviously more for sensitive changes). The dialog that takes place in PRs helps enforce (and sometimes define) our style standards, teach engineers the idioms of a languages they may be new to, and ensure that we're always moving our codebase in the right direction. (They're also a great place to teach people how to write cleaner and less brittle tests!)