Software Engineer

Janestreet; Hong Kong; On-site; HKD 60,000 - 90,000; Full time

Job summary

Janestreet in Hong Kong is looking for Software Engineers to design and build systems that drive the firm. This role involves working across trading, accounting, and foundational infrastructure, emphasizing functional programming with OCaml and Python.

The ideal candidate is a skilled programmer who is curious, collaborative, and eager to tackle interesting problems. At Janestreet, you will contribute to open source and work in a supportive environment.

Qualifications

• Top-notch programming skills and a love for technology.
• Intellectually curious and eager to learn.
• Collaborative and humble, willing to ask questions.

Responsibilities

• Design and build systems that run the firm.
• Solve problems across various teams, including trading and accounting.
• Contribute to open source projects and implement foundational infrastructure.

Skills

Programming skills

Fluency in English

Interest in technology

Tools

OCaml

Python

Job description

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.

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