There are 4 interview rounds + online case. First consists of 2 brain teasers and 2 behavioral, seocnd is focused on your background, third is a technical case, and the 4th is a superday with 3 interviews.
Supposed to be a 30-45 min interview but overran to an hour. 3 fairly simple maths questions but I was nervous so faltered a bit. Then a discussion about why Jane Street, why not just investment banking, I asked lots of questions to the interviewer at the end. Have to be on your toes but they are interesting to talk to
Interview questions [1]
Question 1
angles between hands on a clock
speeds of cars on a race track
Screening call with HR with brain teasers and motivational questions, then behavioral interview with sales trader, then technical interviews, then Assessment center. only got to the second stage. sales trader seemed pretty disinterested, so got rejected