Applied for the technical program manager, university grad role initially. Recruiter reached out and had a quick conversation about the role, my experience (background was a non-CS engineering major) and potential fit. Received email next day that they would schedule me for a phone interview for a non-technical program manager position.
Phone interview was 45 min, a few behavioral questions and then a hypothetical question which involved brainstorming ways to implement a program for release of a specific software. The latter part took about half the interview. As I'm sure others have mentioned, they're mostly looking for inquisitive problem solving and thinking outside the box.
About 2 weeks later, I got invited onsite. Four 45 minute interviews and an informal lunch, all with program managers. A lot of the questions were the same (probably just taken from a generic pool of questions) and focused on general program management and working with teams. Last interviewer asked some curveball questions about cloud computing that I wasn't too familiar with. Everyone was mostly nice and attentive.
By this time in the interview cycle, my experience was a lot different than the tortuous, drawn out descriptions of the interview process that I had read on Glassdoor. However, after the onsite is when the stressful waiting began. In my case, Google opted to do team match before the hiring committee, and so I spent about 1.5 months waiting for a team. Eventually, I went with another offer that had an expiring deadline after realizing that there would not be a team secured for me in time.