@ Rick YG
Congrats on getting an offer from Columbia's IEOR! I was also contacted by Berkeley IEOR several weeks ago and had a casual interview with them. I also had interviews with two Columbia IEOR professors (I thought the interviews went pretty well). However, I haven't heard anything back from Columbia yet (I assumed that it means a waitlist/rejection), but I was admitted by Berkeley's IEOR. Do you know whether Columbia's IEOR has sent out all the offers?