I had a phone screening call from a recruiter, they asked some standard probability questions, bayes rule, and expected value about dices. Overall experience was pretty good. Make sure you prepare your probability
Questions d'entretien [1]
Question 1
Expected value, if throwing a dice, 2 dices and 3 dices with option to reroll.
J'ai postulé en ligne. Le processus a pris 3 semaines. J'ai passé un entretien chez Jane Street
Entretien
I applied online and the interview process was about 3 weeks. I had three rounds of technical interviews with 45 mins each, with increasing difficulties. Questions asked were mostly probability/game strategy questions; I got a few questions regarding dice rolls with some very insane dices lol. The interviewers are nice, and they give small hints and clarifications when I got stuck, which was very helpful. Unfortunately I did not pass the third round, but it was definitely a fun experience.
Questions d'entretien [1]
Question 1
Game1 : a dice roll with a 100-faces dice, labeled from 1 to 100.
1. You get to roll once and receive the amount of dollars labeled on the face, how much would you like to pay for this roll.
2. How much would you pay if you can roll the dice twice if you are unsatisfied with the first outcome?
3. You can roll the dice infinite times, and costs 1 dollar for each roll except the first one. What is your strategy?
Game2: you are competing in a game with 2 other players. with a 21-faces dice (labeled 1-21). All three of you gets to choose a number and then roll the dice. Whoever chose the number closest to the outcome wins. What is your strategy?
another twist: what if all three of you can communicated?
J'ai postulé en ligne. J'ai passé un entretien chez Jane Street en nov. 2022
Entretien
Very smooth. Around 30mins first round 1hr for the second round. First round consisted of easier probability based questions. Second round was similar but harder and longer questions. The interview process if approached in a calm composed manner should be easier to analyse
multiple phone interviews and a full-day Zoom interview. Interviews got longer and longer over time, but every person was very kind and helpful with hints when I got stuck. The questions get harder as the rounds progress and generally don't have a closed form answer in the later rounds
Questions d'entretien [1]
Question 1
they describe the rules of a game and ask if you want to play it based on your expected earnings