Relatively easy compared to other firms - probability and game theory questions centering around Bayes' Law and Nash Equilibria. Make sure you don't slip up as they'll reject you for small mistakes given that the questions are not that hard.
I interviewed at Susquehanna International Group (Philadelphia, PA)
Interview
OA was probability, combinatorics, and logic problems. Not that difficult if you practice. One phone screen. one round was rapid fire math questions as well as a behavioral. Did not get the offer.
Interview questions [1]
Question 1
What is the max entry fee you would take to earn the outcome of a dice roll?
The process included an OA followed by a phone call. The CodeSignal had four questions: two easy and two medium. Overall, it was average difficulty, with matrix familiarity especially useful.
I interviewed at Susquehanna International Group (Sydney)
Interview
After passing online assessment will be a phone interview. The interview is ard 30mins, after checking ur personal information and WAM, the hr asked me 4 math questions. U r required to solve it manually (no calculator) and when u do it u need to say aloud how u think.