Jane Street First Round Interview Experience (Software Engineer at London)

At the beginning of 2025, I got a one-hour coding interview experience with Jane Street.

Jane Street: Global Leading Finance/Trading/Quant Company

Market Position:

Jane Street is a globally leading quantitative trading firm and liquidity provider, founded in 2000, with headquarters in New York and offices in London, Hong Kong, and Amsterdam.

It is known for its heavy reliance on mathematics, statistics, and computer science, using quantitative analysis for automated trading in financial markets.

Technology-Driven:

Jane Street specializes in market-making, providing liquidity for various financial instruments worldwide, including stocks, ETFs, bonds, options, and futures. Their trading model is primarily algorithmic and data-driven, leveraging low-latency technology to identify trading opportunities.

As a technology-driven company, Jane Street develops most of its core trading systems and tools in-house. They heavily use the functional programming language OCaml to build high-performance and reliable trading systems.

Culture & Work Environment：

Collaboration & Academic Atmosphere: Jane Street’s company culture emphasizes teamwork, data transparency, and an academic research environment.

Flat Management Structure: Employees at all levels are encouraged to contribute innovative ideas.

Comprehensive Training: Especially for new hires and fresh graduates, Jane Street provides systematic training to help them ramp up quickly.

Hiring & Career Opportunities：

Jane Street is known for hiring top mathematicians, programmers, and quantitative analysts. They place great emphasis on candidates’ logical thinking, programming skills, and ability to solve complex problems.

Positions include: Quantitative Trader, Researcher, Software Engineer, and Infrastructure Engineer.

What Sets Jane Street Apart:

Jane Street is not just a trading firm; it also has a strong engineering culture.

They contribute to the developer community by open-sourcing various technical tools and research, including OCaml projects.

Industry Standing:

Jane Street is considered one of the leaders in high-frequency and quantitative trading, often compared to firms like Citadel Securities, Two Sigma, and D.E. Shaw. Its innovation and rigorous risk management enable it to perform well even during financial crises.

Interesting Facts:

Jane Street handles billions of dollars in trading volume daily. Although it doesn’t engage in extensive publicity, it has a stellar reputation within the industry.

The company offers competitive compensation and a flexible work environment, attracting top graduates and experienced professionals worldwide.

If you’re interested in quantitative trading and technology development, Jane Street is definitely a career path worth exploring.

Last year, I heard that Jane Street is a famous quantitative trading firm with generous compensations package. So, at the beginning of last year, I submitted my application for a Software Engineer Role. Unfortunately, I did not get any interview opportunities. About three weeks after applying, I received a rejection email (I applied for the Software Engineer position in London).

jane-street-rejection-letter Jane Street First Round Interview Experience (Software Engineer at London)

Rejection Letter/Email from Jane Street London

It’s Best to Include a Cover Letter When Applying to Jane Street

At the beginning of this year, I tried again. I asked ChatGPT to help me write a cover letter. Although it was optional in Jane Street’s application process (they have their own application portal pages), I felt it kinda made a big difference. ChatGPT did a great job helping me improve my English:

Happy New Year 2025! 🎉
I’ve been a Senior Software Engineer at Microsoft Research Cambridge for the past 3.5 years. As I reflect on my journey, one of my key resolutions for this year is to step out of my comfort zone and embrace new challenges. Growth happens outside familiar boundaries, and I’m eager to push myself further.

This year, I’m particularly interested in exploring opportunities at Jane Street. Though I haven’t worked in this industry before, it feels like a natural extension of my background as a crypto trader and enthusiast. The firm’s focus on quantitative trading and its intellectually rigorous environment are incredibly appealing. It’s an exciting prospect to apply my technical expertise and analytical skills in a field that blends finance and technology seamlessly.

Here’s to learning, adapting, and embracing new possibilities in 2025! 🚀

Jane Street First-Round Interview Experience

I quickly got scheduled for the first-round interview, which was a one-hour coding session.

Jane Street Schedule First Round Interview

We received your resume and would like to consider you for a Software Engineering role at Jane Street. If this is not a position you’re interested in, please let me know. Please keep in mind that as we go through the interview process, we will continuously evaluate your potential for all roles at Jane Street.

If you would like to interview for this position, please let me know your availability for an hour long interview over the next two weeks or so, within regular business hours UK time if possible. Our interviewers use https://coderpad.io/ to do some coding exercises, so please be sure to have a computer and internet access for your call. Your interviewer will provide you with a session link for coderpad.io during the call. For reference, coderpad shortlinks look like this: https://cpad.io/012345, and they are valid for an hour.

Our preferred interview method is via Zoom.

While OCaml is our programming language of choice, we encourage you to program in whatever language you’re most comfortable with for the interview, functional or otherwise. To get an idea of what to expect in our programming interviews you can read our blog post which covers what we look for and what we’ll aim to accomplish during the call. You can also learn more about our Software Engineer interview process on our prep page.

We realise many similar positions offer remote work opportunities. I want to be up front that we do not offer that on a general basis. At the moment, almost all software engineers live close enough to the office to commute regularly. Some choose to work in the office almost all the time; others split their working time between the office and their home. However, fully remote work is not something that we typically offer.

Inclusion is extremely important to us – if you require adjustments or have any special requirements, please make us aware as soon as possible, and together we’ll find an interview process that works for you. Lastly, if you receive any offers or deadlines from other firms while interviewing with us please email me with details so we can work with you to expedite our process.

Please let me know if you have any questions and I look forward to hearing from you!

The interview was conducted on CoderPad.io, with the link provided at the start of the session. Unlike Meta or Google, Jane Street’s first-round interview does not use any standard leetcode puzzles.

I was allowed to pick a programming language of my choice. TThe problem wasn’t algorithmically difficult but required a lot of coding. It tested familiarity with data structures like hash tables and priority queues. I ran out of time for the second part (follow-up question) but explained my approach (thoughts) to the interviewer.

Reflection: Why I Got Rejected

Unfortunately, I didn’t pass. I thought I could at least reach the onsite interviews. A week later, Jane Street sent a rejection email, but they didn’t want to provide any feedback.

jane-street-no-feedbacks-after-interview Jane Street First Round Interview Experience (Software Engineer at London)

Jane Street does not provide any interview feedbacks.

We realise that the interview process can leave certain questions unanswered. Though we would like to be able to offer personalised and detailed feedback to everyone, that is unfortunately not part of our process. We appreciate the time you’ve taken to interview with Jane Street, and wish you the best of luck in your search.

I suspect the rejection was due to an initial poor data structure choice and spending too much time clarifying the problem, leaving no time for the second part. Also, I should have verbalized my thought process more while coding.

How long hear back from Jane Street’s first round interview (Software Engineer)?

Jane Street typically responds within one to two weeks after the first-round interview for a Software Engineer position. However, the timeline can vary depending on the volume of candidates and the specific role.

If it’s been over two weeks and you haven’t heard back, you can consider sending a polite follow-up email to your recruiter for an update.

Software Engineer Levels in Jane Street

Jane Street does not have traditional software engineer levels like many other tech companies (e.g., Google’s L3-L7 structure). Instead, their software engineering roles are more fluid and impact-driven.

How Jane Street Handles Seniority:

No formal titles like “Senior” or “Staff Engineer.”
Engineers gain more responsibility naturally as they prove their skills and contributions.
The compensation and influence grow based on performance rather than title.
More experienced engineers take on mentorship, design, and leadership roles organically.

If you’re looking for structured promotions, Jane Street’s system might feel different from typical tech firms. However, it allows engineers to focus on impact rather than chasing promotions.

Considering applying for a Software Engineering Role at Jane Street?

It seems that Jane Street London has many openings (head counts). Jane Street is probably expanding at London at the moment.

jane-street-london-roles-scaled Jane Street First Round Interview Experience (Software Engineer at London)

Jane Street London Opening Positions

The following two links are recommended. Also you can find many interesting videos regarding the Jane Street Interviews on Youtube.

How long can you re-apply to Jane Street after rejections?

Here is the reply:

You can definitely reapply. We usually recommend waiting to reapply until the next year (in the case of current students), or until your experience or circumstances have significantly changed (in the case of experienced hires). This is not a hard and fast rule, but we think it’s a reasonable guideline.

Software Engineer Interview Experience

Interview Tips

Interview Questions

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Jane Street First Round Interview Experience (Software Engineer at London)

It’s Best to Include a Cover Letter When Applying to Jane Street