A Jane Street Software Engineering Mock Interview with Grace and Nolen

Interviews are an important part of Jane Street’s hiring process. We also recognize that they can be stressful, especially if you don’t know what to expect. We’d like to help alleviate some of that stress by sharing a recording of a mock interview.
In the video, two Jane Street software engineers - Grace and Nolen - take us through a typical Jane Street software engineering interview, using a now retired interview question. At the end, they offer some high-level advice on approaching our interviews: how to communicate with your interviewer, how we think about code quality, and how to practice.
00:00 - Introductions from Grace and Nolen
00:48 - Interview begins
02:04 - Grace describes the shape of the interview and what to expect
04:03 - Grace introduces the interview question
05:17 - Nolen talks through his ideas
10:32 - Nolen starts writing code
33:45 - Interview ends
34:10 - Grace and Nolen summarize what we look for in an interview
34:56 - Advice 1: Communication
36:00 - Advice 2: Clear and correct code
36:40 - Advice 3: Practice
The most important piece of advice is to practice. When you practice, make it as much like a real interview as you can: start a timer, talk through your ideas out loud, write out all parts of the problem (yes, even the parts that seem “easy”). That way, when the real thing comes, you’ll be more familiar with the environment.
To find practice problems you can try sites like Leetcode and Hackerrank. While the questions there aren’t exactly what you’ll answer in a Jane Street interview, they’re good sources of algorithmic practice.
We’ve also written some blog posts about Jane Street interviews, including what an engineering interview is like and what we’re looking for in new hires → blog.janestreet.com/what-a-ja...