Job Specifications
Functional Software Engineer – Research & Quant Foundations (RQF)
You must have experience in Functional programming, using one of the following F#, Haskell, Rust, Lisp, Erlang, OCaml, Caml along with Python. You will not be considered if you haven't.
Location: London (Onsite 4/5 days per week)
Experience: 4 years, varying levels of experience being considered.
Hires: 3+
Team: 7-8 engineers + manager
We’re working with a top-tier quantitative research and systematic trading firm operating one of the most advanced trading platforms in the world.
Their systems are fully automated, globally distributed, and run at extreme scale - executing millions of trades per day. Platform resilience, uptime, and operational efficiency are mission-critical.
As a Functional Software Engineer within the Research & Quant Foundations (RQF) group, you’ll sit at the core of the platform, building systems that enable quant researchers to move faster across a vast compute estate. The focus is on abstracting complexity, improving developer experience, and ensuring large-scale research workloads run smoothly and reliably.
This is a high-bar engineering role for people who care deeply about functional design, correctness, and software quality.
What you’ll be working on
A core scheduling platform written in F#, responsible for distributing very large workloads across massive compute farms
Python and .NET SDKs that form the primary day-to-day interface used by researchers
A TypeScript/React UI backed by an F# ASP.NET service, Postgres, and Kubernetes, providing real-time visibility into workload execution
Tooling and frameworks that enable researchers to build and deploy research platforms and express computations over streaming data
Foundational systems designed for performance, safety, expressiveness, and long-term maintainability
The codebase is approximately 75% F#, with the remaining 25% primarily Python and Rust. Day-to-day work includes high-end, production-grade Python, but the engineering culture is strongly rooted in functional programming principles.
What they’re looking for
Strong interest and experience in functional programming
4+ years of software engineering experience in high-bar environments
Excellent programming ability with a deep focus on code quality and design
Experience with one or more of: F#, Haskell, Rust, Lisp, Erlang, OCaml, Caml, or similar
Professional Python experience beyond scripting or notebooks
An engineer who genuinely cares about developer experience
Exposure to compiler work or language tooling is a strong plus
MSc or PhD in Computer Science (or equivalent depth of technical background) is highly desirable
This team hires exceptionally well and is scaling deliberately, with three new hires planned.
If you’re excited by functional programming, large-scale distributed systems, and building foundational tooling that world-class researchers rely on every day, this is a standout opportunity.
About the Company
Our Team at Arcus Search recruit Technical talent, but our ethos is always human connection. With a promise to champion opportunities for all.
By leading with an honest and practical approach, we strive to ultimately enhance the lives of our candidates, clients and employees.
Our talented Consultants are focused within specialism areas covering:
* Project Services
* Software Development
* Core Technology
* Data & BI
* Design & Digital
* Cyber Security
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