I applied online and received a reply very soon after, inviting me to a phone screen. The phone screen was about an hour long and involved 30 minutes of talking about my resume and 30 minutes solving a LeetCode-style problem. I was only able to code a non-optimal solution, but still got invited to the virtual onsite.

The virtual onsite involved three interviews, each an hour long.

The first interview was almost a replica of the phone interview in terms of format, while the other two were far more open-ended and involved verbally discussing potential solutions to more open-ended coding problems. Unlike interviews with comparable firms, it felt like DE Shaw interviewers had free rein to ask whatever caught their fancy, and as a result, the interviews felt a lot more unstructured.

I did reasonably well in all three rounds and was invited to yet another one-hour interview, I believe with a hiring manager. I was under the assumption that this would be more behavioral, but was hit with another LeetCode-style problem. I panicked and wasn't able to provide a robust solution, even though the question itself wasn't particularly hard.

Data structure and algorithm questions.

A couple of open-ended problems that required some knowledge of basic ML techniques, statistics, and probability (no need to write code for these).