First interview is through the phone, roughly 5-10 minutes asking questions about your experience and a brief explanation of the roles available, followed by scheduling for an in-office interview at a local office designed to recruiting. This call is done with a recruiter forwarding you application.
Second part was a full day behavioral interview session, starting from 9-9:30 to 4. Expect standard STAR type behavioral questions between 3-5 different high level members from separate teams. You will be rotating interviews with other recruits in a lobby area, and in between interviews you can chat with other candidates and members from HR and various teams. One of the 3-5 interviews will be a lunch interview where you can ask about projects, company culture, etc.
Third round of interviews occur after a call or email for scheduling a time to meet. This interview is an individual session consisting of technical questions and white board problems. Roughly 3-4 hours or 4-5 questions. You will be asked questions by 1-2 engineers in a specific project teams that they believe you to be fitted for.
After this interview, you will either set up for another round of technical interviews, or receive an offer. Questions ranged from ideas like data structures or algorithm design. Candidates are overall chosen based on they skills, fit in the company's culture, and external factors (such as ability to receive a faster security clearance compared to other candidates).