As I live in a different state, I was scheduled to have entire steps of interviews at once, virtually. People listed for the interview were: HR team (2), research team members interested in me (9) with direct supervisor, Director supervisor of the direct supervisor, and the department head. Not everyone at once but back to back in a row for <=30mins each for each department. Of course, not everyone could show up, but I had chance to talk with HR team, a few research team members, direct supervisor, and direct supervisor of the direct supervisor. I spent most time talking with my research team, especially they asked critical questions for checking my knowledge for the position. Questions were neither very easy nor very hard, but all were expected. If you carefully read the job descriptions and techniques they expect from you, most of the questions would be from there. Plus, the others would be checking if you are lying on your resume. I know I wrote extraordinary amount of techniques for my level of education, and they asked DEEP to see if I'm lying or not. If you are honest, you should be fine. Unfortunately, I did not get an offer, I believe because when I was having the interview I couldn't give them the exact day when I can start working because of VISA.

After a phone interview, they asked me to do an onsite interview which lasted around 2 hours. People from HR and the department that I was applying for interviewed me. No more than 2 people per interview section.