Software Engineer – ON-SITE

Job Overview

API Engineer – C#/Kubernetes – Trading Infrastructure (12-Month Contract, Inside IR35)(No Sponsorship Offered)
We’re hiring an experienced API engineer on a 12-month contract for a top-performing global hedge fund. If you live and breathe backend systems, know how to build battle-hardened APIs in C#, and can wield Kubernetes like a pro—this one’s for you.
You’ll be joining an elite engineering team at the core of the firm’s trading stack, delivering high-performance services that drive execution, data, and automation workflows across the business.
The MissionThis is a hands-on engineering role focused on designing, building, and deploying critical APIs that underpin a multi-strategy global trading platform. Think low-latency comms, resilient services, and cloud-native orchestration – all at scale! You’ll work shoulder-to-shoulder with quants, traders, and infra engineers to push the platform forward.
Expect to operate in a high-trust, high-impact environment where your code hits production fast and clean design matters.
What You’ll Be DoingDesigning and developing RESTful APIs and internal services in modern C# (.NET Core/.NET 6+).Containerising and deploying workloads using Kubernetes across hybrid cloud/on-prem environments.Building performant, observable systems that can be monitored, scaled, and debugged under pressure.Collaborating with cross-functional teams to integrate services with trading systems, data pipelines, and control tooling.Automating builds, CI/CD workflows, and testing pipelines to maintain velocity and reliability.
What We’re Looking ForDeep C#/.NET engineering experience – ideally with distributed systems, messaging, or low-latency APIs.Strong Kubernetes know-how (Helm, Operators, autoscaling, secrets, RBAC, etc.), preferably in production.Familiarity with containerization (Docker), service meshes, and microservices architecture.Background in financial services or trading tech is a big plus – but not a dealbreaker.Experience building robust, testable systems that run 24/7 in demanding environments.Clear communicator who can work independently, take ownership, and hit the ground running.Bachelor’s/Master’s Degree in Computer Science or Engineering from a top-tier/Russell Group university.
The Opportunity12-month contract with high visibility and real impact.Up to £900/day, inside IR35.Work alongside some of the best minds in systematic trading.Tight-knit, engineering-led culture with autonomy, pace, and purpose.