The process began with serveral online tests for maths and logic. They gave a personal interview to get to know the candidate better and evaluate fit for the company/role, then held a technical interview covering maths and logic problems.
Difficult interview
Application
I applied through a recruiter. The process took 3 weeks. I interviewed at Jane Street in Mar 2025
Interview
Four rounds of interviews, the first three online, and the final one is onsite.
The first round is brain teasers and probability problems.
The second round is coding test, relatively easy.
The third round is harder maths and probability problems.
I only had two interviews in the morning during my onsite. One is maths + machine learning, the second one is a "data round" that you explore a dataset and suggest potential ways to train a model with the interviewer.
I thought I did OK. Was sent home after lunch :(
Interview questions [1]
Question 1
You are rolling a dice, each time, you can stop the game and get paid by the face-up amount, or keep going. You can go at most three times, what's the expected gain?
Fun and filled with unexpected questions. The questions rely on fast thinking and fast calculations, and sometimes intuition because there is no sufficient time for me to work through the whole problem.
We started with a bit of small talk, followed by some probability questions. Ended with some basic algebra questions, Make sure to ask questions if you have any. Good experience, feels like the interviewer was trading.
