I submitted my resume at a university campus, where the company held a seminar. Later, I was invited for a written test through an online system. HR person was very helpful, problems were about calculus, statistics, probability and programming. Not difficult problems, but there were 10 of them for 1 hour of time, I'm not sure it's possible to solve all of them correctly within this time. It looks like I solved enough to be invited to the second stage of the interview, where I had a conversation with one of the researchers in the lab. I was asked about my background and was asked to solve further problems, including statistics and machine learning. These were simple problems, even though it takes some time to recover the basics, especially if you graduated from the university many years ago. I thought the interview went well and it was longer than planned, so overall a positive experience. However, I got a rejection few days later.
In my opinion, you should not bother dealing with these guys. They don't really understand the basics of finance (at least those with whom I communicated), don't know what they want and the selection process is inefficient, questions asked during the interview were irrelevant. You should not judge a PhD professional with many years of experience by asking to solve college-level problems. In addition, they have a 2 year non-competitive agreement that would not allow you to work for other competitors, and this period is unpaid (this is the reason they operate in Texas, since it's legal there). In addition, they don't disclose their returns and the general impression about the company is pretty murky.
