How do you manage the code quality of your projects?

Hi, I'm Mariano Focaraccio, Founder & CEO of Gitcolony (http://gitcolony.com). We are working really hard to redefine how software companies manage the code quality of their projects. I'd love to hear about your experience with code review, peer programming and QA processes to understand where the pain points are and make sure we can tackle them! Gitcolony is still very much a beta - there are plenty of rough edges. It'd be great to hear your thoughts, good or bad! Thanks for your time!