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.