I had a 30 minutes phone interview with the team first. they asked about my research in the first part of the interview. in the second part, they describe the position and asked few simple questions about the power supplies and VR. By the end of the same day, I received and email from the manager inviting me for an on-site interview. the on-site interview lasted for about 7 hours of one-on-one technical interviews (about an hour each), including a lunch with the manager.