Jane Street's quant interview is rigorous, emphasizing probability, mental math, game theory, and logic puzzles. It tests deep problem-solving skills, clear communication, and speed, often across multiple high-pressure rounds. Multiple rounds involving maths, probability, coding, games..
Interview questions [1]
Question 1
Alice and Bob each have a coin and flip it until they get a heads. If Bob flipped his coin more times than Alice, what is the expected number of times Alice flipped her coin?
I applied online. I interviewed at Jane Street (London, England) in Jan 2026
Interview
I did a Zoom interview.
The interveiwer was kind and asked me some probability questions.
I stumbled a bit but answered correctly in the end. However, I didn't get an offer so maybe they want someone who answers straight away.
Interview questions [1]
Question 1
Startegy of changing a line.
Is this a realistic strategy? What would change in the real world?
Technical interview round 1 and 2. Two math problems/brain teasers. Round 1 is easy, but round 2 becomes more challenging. Problems are well designed with multiple follow ups. Interviewer super friendly and nice. Great people and nice culture.
Very friendly interviewer and relatively easy questions. Quite organised in their interview process, with clear guidelines as to how to approach the interview. Focus is to explain the rationale and not just get the correct answer.
Interview questions [1]
Question 1
Probability of raining on sunday or saturday based on individual probabilities. Give upper and lower bounds on the probability of the union.