Google Site Reliability Engineer interview questions

I was contacted by a recruiter, and went through a phone screening where they asked me basic data structures and algorithms questions (and the Big O complexity for insert/deletions etc). I then went on to do a phone technical interview, which I was given a preparation demo for a week beforehand, which was very generous of Google. The phone interview was very well conducted, the interviewer quickly made me feel comfortable and asked me some short quick questions about my CV (e.g. when did you last have a bug with socket.io? How did you resolve it?). I was then asked a coding question which was quite complex, and the more I tried to simplify it, the more the answer became clear, however I wasn't confident or skilled enough to approach it without wasting the interviewers time. The interviewers and recruiters are brilliant, they genuinely seem to be egging you on and trying to back you up, I beleive they understand how these interviews can be, and are very good at making you feel you can pass it!