I'm not sure if the interview process is uniform across corporate headquarters - but here's my experience.
I had a phone screen with the hiring manager (who is a director). This went well, so after that, I met for lunch with him and 2 potential colleagues. I think they did this to keep the process moving along while they coordinated my interview day (which they call an "audition") and to see if there was a cultural fit.
Lunch went well - casual but focused. Shortly after that, I went in for my "audition" with technical team members and business/product people. The day (which lasted about 4 hours including lunch) focused on some real world needs they have, and I had to come up with and action plan. It was very collaborative, and a good way for us to assess each other. This was a very different type of interview than the one I experienced at Amazon (where I'm coming from), as we got a lot of the "behavioral" type questions out of the way. I liked the format because they got to see how I actually think and work, and I got a lot of context and a good sense of what their expectations and needs are.
They came back with an offer in a few days which I accepted. Overall, the experience was very positive.