I was first contacted roughly 6 weeks after sending in my application to arrange a phone interview with someone in HR (I received an email to arrange a time, so it wasn't a spontaneous phone call). The questions asked were typical of an initial interview (tell me about yourself, what is your 5-year plan, what is a weakness, etc.)
After the phone interview, it was over a month until I next heard back from HR, where an in-person interview session was then arranged. The session consisted of two 45-minute interviews, followed by a 30-minute math test. I interviewed with two of the Team Leads/Senior Scientists for the first interview, then the second interview was with three of the Scientists. Everyone was extremely nice, which made the interview process feel more like a natural conversation. The questions were mostly regarding my previous work and projects I was involved in, and also a few questions regarding my ability to work in a team environment.
I was contacted the next day for a final interview with the VP of Research & Development. It was a short, 30-minute interview which had very similar questions asked in the previous interviews.
Overall, I did not enjoy how long the job application/interview process (around 4 months total). I think this is due to HR, because the longest length of time was between submitting my job application to receiving my first in-person interview. After that, the next interview was promptly organized within 48-hours and I received the job offer within a week.