Very difficult probability and brain teasers that is taken online followed by an phone interview. Make sure you practice your stats and logic before you take the test.
I applied online. I interviewed at Susquehanna International Group
Interview
First was a screening with math questions. There are 16 questions which range in difficulty. I did not manage to make it pass this stage. The stage after that is phone call with a recruiter.
Interview questions [1]
Question 1
Standard probability questions, binomial distributions, gamma distributions, bayes etc.