Verified by our engine · Posted 3mo ago

Jane Street

Software Engineer

Jane Street · Software Engineering

London

Mid-level Still listed after 3 months

SoftwarePython

Last seen 2h ago

Posted
3mo ago

Posted on 7 August 2026

Workplace
Not specified

Work model not stated

Salary
Not disclosed

Salary range not shared by the company

Visa sponsorship
Not specified

Visa sponsorship details unknown

Listing history First seen 60+ days ago
  • First seen 60+ days ago. We first saw this listing on 10 Sept 2026. That is when we found it, not necessarily when it was posted.

First seen 10 Sept 2026. Last checked 11 Nov, 22:17 UTC. We read each employer's own career page on a cycle and record what changes; this is what we observed, not a verdict on the role.

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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:

A top-notch programmer with a love for technology

Intellectually curious, collaborative, and eager to learn

Humble and unafraid to ask questions and admit mistakes

Fluent in English

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 Jane Street

Jane Street's European postings are all London. It's a proprietary trading firm building its own trading and research infrastructure in OCaml — the interview process is famously technical, and the roles here are engineering, not finance, despite the industry.

Apply at Jane Street