Software Engineer

Jane Street; City Of London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A leading financial company in London seeks Software Engineers to design and build critical systems and tools. You'll collaborate across teams, solving real problems without needing experience in OCaml or Python. Ideal candidates love technology, are eager to learn, and can admit mistakes. This role values programming skills over specific language knowledge.

Qualifications

• Strong programming ability with a love for technology.
• Intellectually curious, collaborative, and eager to learn.
• Humble and unafraid to ask questions and admit mistakes.
• Ability to learn new languages and concepts.

Responsibilities

• Design and build the systems and tools that run the firm.
• Collaborate across teams (trading desks, accounting, infrastructure) to solve real problems.
• Develop and maintain foundational infrastructure.

Skills

Strong programming ability

Curiosity and willingness to learn

Collaborative spirit

Ability to ask questions

Tools

OCaml

Python

Job description

Overview

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.

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

For more information about our 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 [e-mail].

Responsibilities

• Design and build the systems and tools that run the firm
• Collaborate across teams (trading desks, accounting, infrastructure) to solve real problems
• Develop and maintain foundational infrastructure, including monitoring, risk models, and open source projects

qualifications

• Strong programming ability with a love for technology
• Intellectually curious, collaborative, and eager to learn
• Humility and willingness to ask questions and admit mistakes
• Ability to learn new languages and concepts; experience in OCaml or Python is not required

Note: This description reflects the content of the job listing without including form fields or unrelated boilerplate.