There were a total of 5 interviews and the process lasted a little over a month. The recruiter kept me apprised of each step and after each interview the interviewer gave you a run down of what to expect in the next round of interviews.
Overall, while the number of interviews did seem like a lot, I had a really good grasp on the role and what would be expected should I be offered the position. They also left a lot of room for you to ask questions and their online handbook allows you to see how the company functions as it has a very clear transparency model about the culture inside GitLab.