WorldQuant Quantitative Researcher interview questions

I was contacted by HR, phone interview about my background. Then I was invited to take part in written test at the office. About 40 questions 2-5 min time limit each. Then I was invited to 3 consequent hour interviews. Topics: probability theory (correlation, expectation), complexity of algorithms, discrete mathematics (graphs connectivity).

My initial communication is by email coincident with their early recruitment events in my country. The first round to filter out candidate is by having all the candidates taking written exams. Then they start phone call to a subset of test takers who look promising. I had 5 subsequent phone interviews before getting job offers.