First round is very basic behavioral questions, why AS, what is the BREAD process, and many questions regarding by educational background (both high school and college). They are genuinely interested in getting to know my extracurriculars, what I was the most proud of, etc. Overall, felt more like a conversation rather than a stressful interview.
The second round was the tricky part: first hour was behavioral and situational questions, such as what would you do if your client suddenly cancels meetings, etc. The hardest part by far was the case study: you have 10 minutes to find 4 experts on two different topics. Finding someone in itself is not hard, but because of time constraint, I found myself to be panicking. They are very meticulous when gong over the chosen experts, his pros and cons, what would be his added value, why I thought this would be a great fit, etc. Then you finish by choosing one of the experts and calling him/her (role play), and you have to pretend at all times that you are an actual associate (you can't stop in the middle to ask questions).
Last round was with VP, another hour of behavioral. Here, you are really going to dig deep in what you did until now, your past KPIs, your ambition, your work ethics etc. I was also asked what other jobs I applied to and how AS stands out of all of them. He strongly discouraged me not to give pre-made answers, but genuinely listen to the questions and say what I think.
One advice that my HR gave me is that AS knows that most of its associates use it as a stepping stone before heading somewhere else. Therefore you should have a clear end goal in the long term, and how AS will help you achieve that goal. They want to know what you will REALLY get out of this experience.