Jane Street Software Engineer Interview Questions
& Process
Real candidates share what happened, how many rounds they had,
and how the experience turned out.
Based on 349 interview experiences · FREE TO READ
Candidate interview experiences
First-hand accounts from people who interviewed at Jane Street.
Jane Street
Software Engineer Intern
Intern Easy Neutral experience No offer 1 round
Interview process
Technical screen
Interview formats
Coding
I skipped the online assessment and was directly contacted for a coding interview. It was quite dry. They didn't ask any behavioral questions and jumped straight into coding. The coding question itself was super easy - a simple stack problem of keeping track of parantheses. The extension asked to make a visual editor (so it was a bit more OOP) and simply remember the positions of the parantheses from the previous subtask and do some string manipulations depending on if you encountered a paranthesis there.
Confirmed questions1 question
- Design a visual code editor that collapses code blocks.
Jane Street
Software Engineer
Entry Average Neutral experience No offer 4 rounds
Interview process
Recruiter call Phone screen Onsite Onsite
Interview formats
Coding Technical System Design Coding
There was a screening call with a LeetCode easy question, followed by an internal recruiter call. The onsite portion included a system design interview and a LeetCode medium-ish coding interview. It was a decent experience overall, but I noticed a few things: one interviewer asked a potentially discriminatory question about my origin, which is concerning under the UK's Equality Act 2010. Also, one interviewer seemed unfamiliar with C++, which was disappointing as I'm a C++ developer. They also had a policy about not discussing questions, which I disagree with as it hinders transparency. Having the onsite interview take up the whole day is demanding on time and energy. Finally, their blanket policy of not providing feedback makes reapplying feel pointless.
Confirmed questions2 questions
- Design a file system.
- How to efficiently hash an immutable tree structure and compare it to a remote via an API?
Jane Street
Software Engineer
Mid Difficult Positive experience No offer 2 rounds
Interview process
Technical screen Onsite
Interview formats
Coding Technical
It started with a remote coding interview, then moved to an onsite interview. There were two questions in the morning. They were Leetcode medium to hard difficulty, with a strong emphasis on communication. The second question in the morning was harder. I didn't pass the morning interviews.
Confirmed questions1 question
- What were the Leetcode medium-ish questions asked? (Note: Participants were asked not to share details.)
Jane Street Software Engineer Interview Questions
Quoted word for word from Jane Street interview reports.
“For a given string like "aaabbaa", can you provide a list of tuples indicating the consecutive character and its count? For example, [('a', 3), ('b', 2), ('a', 2)].”
Read reports →“Write a method that takes an integer and an array, and rotates the array to the right n times, ensuring constant space and linear time complexity.”
Read reports →“Can you write a function to generate a power set, represented as a list of lists, from an input set that's given as a list?”
Read reports →“A basketball player makes his first free throw and misses the second. From then on, his probability of making the next free throw is the proportion of his previous shots made. What is the probability he makes 50 out of the first 100 shots?”
Read reports →“Given a 2D board with two piece types, create a class that allows adding pieces to a column (causing upward shifts) and checks for columns or rows filled with identical pieces.”
Read report →“Given 10 ropes with red and blue ends, where a red end can only connect to a blue end, calculate the expected value of cycles.”
Read report →“Can you find the common prefix and suffix words in two lists of strings, and then return the remaining lists? For example, if the lists are [cat, dog, dog, elephant] and [cat, dog, shark, elephant], the common prefix is [cat, dog], the common suffix is [elephant], and the remaining lists are [] and [shark].”
Read report →“Explain why this garbage collection algorithm doesn't work: Counter incremented when a pointer to memory is created, decremented when pointer is removed. Deallocate when counter is 0.”
Read report →“Given 2 identical plates that shatter if dropped from above a certain story height, and a 100-story building, what's the minimum number of drops needed to find the critical story height?”
Read report →Formats, difficulty and experience
Across all 349 Jane Street interview reports.