This was the most extensive interview process I have gone through in my career. The interviews themselves were not exceptionally difficult, but the number of them was ridiculous. It started with a phone interview, followed by a prep call for the interview series. The first interview was a pre-interview interview and was an hour long. It was essentially a traditional interview. After passing that, then the series of 4 more interviews began. Personally, I think 6 interviews is ridiculous, especially if you get through all of them and then are told you didn't get the job. I put a minimum of an hour of prep into each of these, plus each interview being an hour long, totaling 15 hours or so dedicated to just interviewing. I will not be applying here again and risk wasting that much time on one position just to get denied.