Full Stack C# Developer | Trading Systems | Contract Inside IR35

Senior Full Stack C# Developer | Contract| Inside IR35 | LondonOur investment banking clients is seeking a Senior Full Stack Developer to join its Front Office FX technology team, building and enhancing business-critical systems used across London, New York and Singapore.This role sits within the FX Deal Capture team and is ideal for an experienced engineer who enjoys designing, building and supporting large-scale distributed applications.You’ll work on systems responsible for trade capture, post-trade workflows and strategic enhancements used daily by traders and operational teams across the bank.What You’ll Be DoingBuilding new features across a modern C#/.NET platformDesigning and developing REST APIs and backend servicesEnhancing deal capture and post-trade processing systemsWorking on messaging and event-driven architecture initiativesRefactoring and modernising existing applicationsCollaborating with developers, business users and technology stakeholdersTaking ownership of deliveries across the full SDLEssential SkillsStrong C# and .NET /.NET Core development experienceExperience building REST APIs and enterprise applicationsStrong understanding of software architecture and design patternsTDD and automated testing experienceDatabase development experienceExperience working on large-scale, business-critical systemsDesirable SkillsKafkaIBM MQReactTypeScriptPythonFront Office or financial markets experienceAI-assisted development tools such as Claude Code, Copilot or similar #J-18808-Ljbffr