Netflix Senior Software Engineer interview questions

I was contacted by the company's recruiter. After a phone interview with the hiring manager, I was brought for an on site interview. I have talked to three engineers, the hiring manager and an HR person.

Was called by hiring manager and he was really good technically. He asked some of the fundamental Java questions like what's abstraction, OOPS concepts, how to scale an application for huge set of data ? I later got 1:1 interview and they flex me to onsite. Very good setup and interviewers at onsite were on time. First interviewer asked some algorithm on how to distirubute messages to different devices whenever there is some event. Second interviewer from marketing not much technical. Third interviewer asked how to maintain user information when user hits netflix site across different servers?. I gave him answer by session replication, cookies or stroing data in common storage . I'm not sure what he was looking for he was not clear interms of the question itself.