3 rounds, two phone interviews, and an on-site interview. SIG employees and recruiters are friendly, play a lot of poker. I had the first phone interview two days ago with the head of recruiting team. We talked about my resume and background, and then she gave me 3 math/probability questions which were quite not easy. I solved all of them and she invited me to the next round which I had today with one of the traders. The difficulty of the problems were little higher but not too bad. I solved all the problems here, too and I waiting for a response from them.