I'll start off by saying that I've never been through a more comprehensive and positive interview process, than I just went though with Unity.
The HR team is incredibly helpful, supportive, and always kept me in the loop (thanks Anne-Sophie!).
The entire process took about 6 weeks, although I may have contributed to the length of the process because I applied for TWO positions almost simultaneously.
It included a phone screen, an initial interview with the hiring manager, a "technical" interview to test actual know-how, interviews with peers, and finally an interview with the Senior Director of Product Marketing.
The process actually allowed me to learn much more about Unity than I had previously known. I left each interview having learned something new, and with an increased level of motivation and excitement.
Like I said at the start of this review, I've never experienced such a great interview process. Unity's processes are several steps above the rest!
Keep up the great work!