Two Sigma Quantitative Analyst interview questions

The 1st round is general phone interview, usually HR. The 2nd round is a programming test via Web based on HackerRank, which takes about 2 hours. . The 3 rd round is a technical interview

Phone call with HR, just selling the company, then 2 hour programming test (same questions others posted, but they seem to be different now). The time limit is quite strict and the website they use is very buggy. I finished with only 3 minutes left, and got nothing else on programming. Two more calls with quants, then full day onsite with 7 or 8 people. Most had fairly in-depth discussion on my research, followed by 2 or 3 brainteasers. Most interviewers were Chinese, some friendly and others less so. One barely spoke English and was very taciturn, so I couldn't tell if he understood anything I said. The last one was an MD who I didn't do as well on, but he seemed to dislike me from the outset and said they want winners of IMO and similar competitions, not experienced researchers, so it probably didn't matter. Finally two HR people with behavioral questions. Rejected a week later. Seemed like a great place, but very long process and some pretty random questions.