My interview was two approximately 30 minute long behavioral interviews. While you are waiting to go in, Deloitte has a few recruiters outside whose job is to greet you and answer any questions you may have. Everyone is extremely friendly and easy to talk to. The greeters help calm you down and make the process much more relaxed and comfortable. The interviews are more like a conversation than them drilling you with questions. They're trying to see if you can hold a conversation and if you are well-spoken or not.