I applied online and within 1 week I had a phone screen with a recruiter. This was more just them telling me about the ACE program and making sure I was still interested. After that, they had me do a very lengthy personality quiz. This was the hardest personality quiz I've ever done, because it gives you a group of statements that all sound good and you have to choose the one that applies most to you and the one that applies least to you. So, every question, you feel as if you're saying that something which sounds good doesn't apply to you; and quite often you might feel like all the items apply to you equally so it is even more frustrating to try and pick the one that least applies. However, if you treat it the same as any other personality quiz and just answer honestly without worrying about whether or not something might sound bad, then you'll probably do fine.
After passing that, they have you do an online automated interview with HireVue. This basically is just you sitting down with a webcam and answering pre-recorded questions. Your answers are recorded and sent to the hiring manager for review to decide if they want to proceed to real interviews. This is a little awkward at first since you can't make any sort of human connection with your audience. However, they have a handful of practice questions that you can do as many times as you like and review the recording each time. Just keep answering those practice questions until you get over the awkwardness and it feels natural. Also take advantage of the ability to review the recordings so that you can make sure your lighting, background, etc. are optimal. Make sure to dress just as well as you would for an onsite interview.
A few days after submitting my recorded interview (~10 days since applying at this point), I was contacted to schedule 3 final interviews; one with the manager of the ACE program, one with the Professional Services Manager at my local office, and one with my local Technical Lead. I was contacted on a Tuesday and they initially asked for my availability for that week and the following, but then said they had to push interviews back to the week after the following (I later found out that some of the interviewers had vacations, projects, etc. in the way). I requested to have all three interviews on the same day so that I could just request one day off and get it all over with; they were very accommodating in this regard.
Two of the interviews were onsite at the local office and one was on the phone. All three lasted 45~60 minutes each. There weren't many technical questions, even from the technical lead. Most of the questions seemed geared towards figuring out if I was cultural fit and shared the same passion for technology as the rest of the team. The PS Manager seemed primarily interested in my thought process when answering questions; he was definitely more interested in the "why" than the "what". All three interviewers seemed to know exactly what they were looking for and knew all the right questions to ask.
After the interviews, I sent all of the interviewers thank you notes. Two days later (about a month after applying), I received an offer. They offered me a position in a different practice than what was originally posted; the practice offered is better aligned with my skills, interests, and experience. Had this one been posted to begin with, I would have applied for it instead of the other one.