This are two onsite interview and each one lasts for about 30 minutes. One group goes over my CV and asks me about the academic background, some projects, etc. Because I have worked on some quantitative trading projects before, the questions focus on what you think about statistical model, whether the prediction accuracy based on training sample or independent test sample. The other group asks the same questions. I don'r think I perform well and so interview doesn't last long.

two phone screens. some interviewers were nice and others were more strict, lots of interesting math and research discussed. got asked a flurry of technicals, ramping up in difficulty each time, and even some open ended questions where they explicitly said there is no interview-tractable solution and just wanted to hear my ideas for an approach