I was initially contacted for a phone screen which was about 30 minutes with an internal HR rep. They asked salary expectations as well as to go over my experience generally. From there the individual I spoke with set up a phone call with the hiring manager. This phone call was 45-60 minutes. After this phone call I received an invitation to interview in person at the HQ offices which was four 30 minute interviews, back to back with different individuals. It ended up being a total of 2.5 hours. I then waited 2-3 weeks and received my offer.