Firstly the HR will contact you with the information to book the travel. The flight and hotel expenses just went through the company's bill. You can also book the car rental, and have a look at San Francisco before the day of the interview. The reimbursement policy is pretty generous. I interviewed with three teams. Most of the interviewer are team manager. The first team asked a lot about the projects on my resume, as well as some knowledge might be used in their group. And they also ask something about basic language usage. The second and third group asked some algorithms questions, they are just common questions which you can find in leetcode.