📍
London, UK

Software Engineer

1 year experience
Finance
Software engineering
Posted:
December 29, 2025

Jane Street

Quantitative trading firm
87
Palpable Score
Apply >view company >

About the Position

We’re looking for Software Engineers who want to help us design and build the systems and tools that run the firm. You’ll find Software Engineers in all parts of Jane Street, solving real problems in critical areas ranging from trading desks to our accounting team, as well as building foundational infrastructure, whether that means implementing network monitoring or risk models.

We are big believers in functional programming and, using OCaml, a statically -typed functional programming language, as our primary tool. More recently, Python has become a vital part of Jane Street’s research and trading work, acting as the go-to language for data analysis, visualization, and machine learning.

Beyond our own environment, we also recognize the value of open source software, leveraging it in our daily work and releasing over a million lines of our own code as open source. We’re also always looking for ways to expand open source projects, and provide ongoing support to things like Mercurial, the OCaml compiler, and the OPAM package manager. That said, we’re interested in talented engineers with experience in any language—most of us came in with little to no practical experience in OCaml before we joined.

If you’d like to learn more, you can read about our interview process and meet some of our newest hires.

About You

We don’t expect you to have a background in functional programming, OCaml, Python, finance, or any other specific field—we’re looking for smart programmers who enjoy solving interesting problems. We’re more interested in how you think and learn than what you currently know. You should be:

If you'd like to get an idea of what we cover in our software engineering interview process, you can visit our interview prep page.

If you're a recruiting agency and want to partner with us, please reach out to agency-partnerships@janestreet.com.

About the company

Jane Street

Company overview
Jane Street is a quantitative trading firm and liquidity provider that makes markets across a broad range of asset classes. Jane Street builds much of the company’s technology in-house, with software engineering and research tightly linked to trading. Jane Street also runs a public engineering blog and open-source work that reflects a deep focus on programming languages, performance, and data systems. Jane Street serves institutional clients through trading and liquidity services alongside proprietary trading activity.

Locations and presence

Jane Street has major offices in New York, London, Hong Kong, Singapore, Amsterdam, and a presence in Chicago. Hiring is office-centered for most roles, with many processes culminating in in-person final rounds in a Jane Street office.

Palpable Score

87
/ 100
Jane Street offers unusually strong early-career access through recurring internships and multiple entry programs, backed by clear pay transparency and high compensation. The strongest signals are hands-on training, mentorship, and real project ownership for interns and new grads, plus benefits that reduce early-career financial stress. The main limiter is that Jane Street does not publish cohort outcomes like promotion rates or internship-to-full-time conversion rates, so outcomes scoring relies on indirect public signals.
view full company profile >

Related jobs

📍
United Kingdom
Cleo
Commercial Associate
January 22, 2026
view job >
📍
Warsaw, Poland
Cleo
Product Engineer - Ruby | Poland
January 22, 2026
view job >
📍
United Kingdom
Cleo
Graduate Machine Learning Engineer
January 22, 2026
view job >
📍
United Kingdom
Cleo
Data Analyst, Fraud
January 22, 2026
view job >