Role: Contract C# .NET Developer

Domain: Commodities trading

Day rate: £700-750/d (outside IR35)

Location: London (hybrid - 3 days per week)

Contract: 12 months (strong extension scope)

X4 Technology are partnered with a well-backed commodity trading firm in London offering an exciting outside IR35 contract opportunity for an experienced C# .NET Developer. You'll play a key role in a major tech transformation, evolving their core trading systems to a scalable data-first model - with a focus on performance, scalability, resilience and smarter system integration.

You’ll be integral to reshaping the architecture of a high-performance trading platform, building new services, optimising real-time data flows and leading the charge in adopting best practices in software engineering across the .NET ecosystem.

Responsibilities of the Contract .NET Developer (Commodities)

• Designing and developing C# .NET Core applications supporting real-time trading workflows and analytics.
• Developing and consuming RESTful and gRPC APIs in a microservices environment.
• Building distributed, event-driven services using Kafka or Azure Event Hubs.
• Implementing scalable cloud-native solutions on Azure (Azure Functions, Service Bus)
• Working with relational databases (SQL Server) and NoSQL technologies (MongoDB, CosmosDB).
• Automating CI/CD pipelines via Azure DevOps, improving deployment frequency and code reliability.
• Collaborating closely with infrastructure and DevOps teams to ensure robust, secure and maintainable deployments (Docker, Kubernetes).

Requirements for the Contract .NET Developer (Commodities)

• Proven experience delivering enterprise-grade solutions with C# .NET Core in production environments.
• Strong background in distributed systems and messaging technologies (Kafka, Event Hubs, or similar).
• Solid understanding of modern API architecture (REST, gRPC) and domain-driven design.
• Proficiency in both SQL and NoSQL database technologies.
• Hands-on experience with Azure and containerisation (Docker, Kubernetes).
• Strong advocate for engineering best practices: TDD, automated testing, CI/CD, Git workflows.

This is a unique opportunity to join one of London’s most exciting commodity trading houses, supporting a major transformation programme. The role is paying £700-750/d on an outside IR35 basis.

First stage interviews are being lined up for W/C 28th April, so please apply online for immediate consideration.