2025 Jane Street SWE intern candidates describe two stages after the application: a live first-round interview of 30 to 60 minutes with a Jane Street engineer on one coding problem, then an in-person final day of about four coding interviews at the office. First-round problems were a stack task, a data-structure class, and a class that stores key-value pairs; the interviewer worked through the problem with the candidate and suggested refinements.
Every 2025 report on this page ended without an offer, including one where the candidate solved the problem correctly. The final day can end early: in one New York report, candidates who had not passed the first two interviews were sent home at lunch.
Jane Street interview process round by round
| Round | Duration | What candidates reported |
|---|---|---|
| Application review | About 1-2 weeks | A person reads the application; a July 2025 intern was contacted to schedule within two weeks |
| First-round technical (Zoom) | 30-60 min | One coding problem with a current engineer, who suggests refinements |
| Final day (in person) | Most of a day | Office tour, about four coding interviews, lunch, early exit for those not passing |
| Q and A | Short | A question-and-answer session after the interviews in one 2026 report |
Jane Street interview reports from 2025
These come from self-reported write-ups on Taro (jointaro.com). Each is one candidate’s account.
- Software engineering intern, New York (March 2025, no offer). In-person final: an hour-long tour, then four interview rounds the candidate called very intense. Lunch came after the second interview, and candidates who had not passed were sent home after round two.
- Software engineering intern, New York (July 2025, no offer). Contacted within two weeks of applying. One call of about an hour with a current software engineer on a single programming problem. The interviewer did not run the code but suggested refinements and flagged issues. The candidate reached a correct solution.
- Software engineer intern, New York (September 2025, no offer). A 30-minute first round with one standard data-structure problem built on a stack and last-in-first-out logic. Suggested prep: two pointers, sliding window and stacks.
- SWE intern, New York (October 2025, no offer). First round of an introduction and a data-structure class question, then an on-site round. The candidate praised a fast recruiter response and a friendly interviewer who explained the process and helped with tricky parts.
- Software engineer intern, United States (October 2025, no offer). One first-round question on distributed web systems: implement a class that handles key-value pairs. The candidate understood that strong performers move to a final day of two to four more rounds.
Detailed interview experiences
Experience 1: SWE intern, New York, in-person final day (March 2025)
Profile: Undergraduate who passed the first round.
Final day: The day opened with an hour-long office tour. Four interviews followed, which the candidate described as very intense. Lunch was provided after the second interview, and that was the cut point: candidates who had not passed the first two were sent home.
Result: No offer, rated neutral.
Takeaways
- What decided it: Consistency across back-to-back rounds; there is no recovering from two weak morning interviews.
- Common fail: Running out of energy by the second hour.
- How to practice: Do two 60-minute mock interviews back to back with a short break, out loud, with someone adding requirements.
Experience 2: SWE intern, New York, correct answer but no offer (July 2025)
Profile: Summer intern applicant contacted within two weeks of applying.
First round: About an hour on one problem with a current software engineer. They worked through it together; the interviewer did not run the code but suggested refinements and pointed out issues. The Taro entry also mentions a system design question where the candidate implemented a class representing the system.
Result: No offer, rated positive.
Takeaways
- What decided it: Not stated, but Jane Street says it weighs how you think and communicate over the final solution.
- Common fail: Treating the interviewer’s suggestions as interruptions rather than collaboration.
- How to practice: Record a mock and check how often you explain a choice before coding it.
Experience 3: SWE intern, New York, short stack problem (September 2025)
Profile: Summer intern applicant.
First round: 30 minutes, one LeetCode-like data-structure problem using a stack and LIFO logic.
Result: No offer, rated positive.
Takeaways
- How to practice: The candidate’s own advice: two pointers, sliding window and stacks. Write them in your strongest language without looking up APIs.
Experience 4: SWE intern, key-value store class (October 2025)
Profile: US intern applicant.
First round: One question set in distributed web systems: implement a class to handle key-value pairs.
Result: No offer, rated neutral.
Takeaways
- Common fail: Jumping to distributed-systems vocabulary before a correct single-node class works.
- How to practice: Build a key-value class, then add TTL, versioning and transactions one at a time, with tests for each.
Experience 5: SWE intern, New York, first round to on-site (October 2025)
Profile: Summer intern applicant.
Process: A short introduction and a data-structure class question in the first round, then an on-site round whose questions the candidate did not describe. The interviewer explained the process and helped with tricky parts.
Result: No offer, rated positive.
Jane Street interview questions that come up often
First round
- Implement a class that stores key-value pairs, then extend it
- A stack problem built on last-in-first-out rules
- A data-structure class design question
- One open-ended programming problem worked through for about an hour
Final day
- A series of collaborative coding problems, about four interviews
- Follow-up extensions on each problem rather than new puzzles
- A question-and-answer session at the end
Behavioral
- Tell me about yourself
- Do you have experience with functional programming?
- Questions for the interviewer
Jane Street behavioral questions in these reports
There is no separate behavioral round in these reports; collaboration is judged during coding. Sample answers to the short questions that do come up are on the Jane Street behavioral interview questions page. The official process, pay and technical answers are on the Jane Street interview questions page.
Jane Street interview tips from these reports
First round
- 30 to 60 minutes on one problem with a current engineer.
- Class and data-structure design came up more than classic puzzles.
Final day
- In person, about four interviews, with a cut after the second.
- Practice stamina: two long mocks back to back.
Communication
- A correct solution alone did not get an offer in July 2025.
- Take the interviewer’s suggestions and build on them out loud.
Sources
- Taro: SWE intern, New York, March 2025
- Taro: SWE intern, New York, July 2025
- Taro: SWE intern, New York, September 2025
- Taro: SWE intern, New York, October 2025
- Taro: SWE intern, United States, October 2025
- Jane Street: preparing for a software engineering interview
- Q and A session and functional programming question: Glassdoor Jane Street interview reviews (Cambridge, England intern; a 2026 onsite review)
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