I have worked with them for over 12 years now so they know what we need and how to work best with our team of developers/engineers in order to get it done right. There are no complaints about their product or services. Excellent! We've been working closely with these guys since 2005 doing web applications that were used by millions of customers around the world. They helped us build some very complex systems from scratch but didn't do any custom coding - just got things up and running quickly while we developed everything else ourselves. So far, there's nothing bad to say about my experience with ATG.