I have seen some people say to study the packet, along with some extras to show you've done some research, have some TMAAT answers ready, and you'll be fine. I am on the Atlas Recruiting FB page, and saw that at least one of the active Atlas pilots on there has strongly suggested a professional interview prep service. I haven't had a formal interview in decades, and after weighing every option out there I really want Atlas to be my final job. So, I am strongly considering doing that even though some seem to think the Atlas interview is laid back enough that it would be a waste of money.