WorldQuant interview questions

Many short stages and long pauses between stages. The process took a very long time. In some rounds, interviewers seem not to focus on interviews or are willing to access candidate capabilities. I felt wasted time for both sides in such rounds, probably due to their highly urgent tasks.

first round is online assessment (need about 3-4 hrs to complete, all about math, a little bit difficult), after passing the first round, you will interview with HR, two quants (each for 30 minutes, asking behavior question, math question and brain teaser) -->?