Took about 2 weeks. First step was an excel problem which was fairly straightforward. The second interview was over the phone where I got asked one question similar to those posted on their website
Interview questions [1]
Question 1
Excel: work out some availability problems for a bakery
the interview is filling with chill vibe, easy going and highly professional. remember to dress formal and do not be late ! i beliebe that jane street is a very nice company!