Two Sigma Systems Support Engineer Position interview questions

I was referred by a friend who works there. The process was fairly quick but slightly messy. One person from HR scheduled the 1st interview with another HR person. Then that person had to scheduled another phone interview for the technical part. That's where it gets slightly messy, apparently they had to scramble for the second interviewer and contacted me after I emailed them for an update. The second interview was not so bad, he asked great questions. Unfortunately he had a rather thick accent and likes to mumble. I had to ask him quite a few times to repeat the questions. To HR: Try not to scramble for interviewers at the last minute. Do not set up potential candidates with people that are fairly new and/or have a slightly difficult accent to understand.