I got the opportunity through internal referral. I passed an technical phone screening and was invited to an on-site. I had 5 interviews in total. Two coding, two system design, one with manager (on PhD research + a quick coding exercise). The technical questions were not too difficult, but I was unprepared for the system design problems. One of the interviewers kept walking around in the room and was really distracting and annoying. I couldn't focus on solving the problem and didn't do well in that session. The interviewing schedule was not the best. I was scheduled to have lunch at 2pm PST, but considering I'm from a couple time zones east of PST, I was already way too hungry to have lunch at that time. Perhaps a low blood sugar level also contributed to my impaired thinking abilities.