Senior Software Engineer C# - FLEXIBLE WORKING

Senior Software Engineer | ~£950/day Outside IR35 | 6-months initial contract | London Industry: Trading Job Type: Contract - 6-month initial Our client is building the next generation of execution and order management (EMS/OMS) infrastructure for global commodities trading. You will join a small, fast-moving engineering team designing and delivering a cloud-native trading platform from the ground up, tightly integrated with risk, pricing, and market data systems to support high-performance trading environments. This is a senior, hands-on role for an engineer who wants end-to-end ownership — from low-level protocol integration through to distributed execution services and trader-facing tooling. Develop low-latency, distributed execution services with a strong focus on correctness, resilience, and performance under load. Collaborate closely with traders, quants, and risk engineers to translate trading workflows and execution strategies into robust production systems. Ensure seamless integration with risk systems, including pre-trade checks, position tracking, and post-trade processing. Proven experience building execution systems and/or order management systems in production. Strong systems engineering fundamentals, including concurrency, distributed systems, networking, performance, and correctness under pressure. Production experience in at least one of C++, Rust, or Python, with willingness to work across multiple languages. Demonstrated ability to deliver production systems with a strong bias towards shipping, iteration, and user feedback. Familiarity with distributed data and event-driven systems (e.g. Experience with observability, monitoring, testing, and production incident response in live systems. Experience in commodities markets (energy, metals, agriculture, freight) or other complex, multi-venue asset classes. Exposure to real-time risk systems, including pre-trade controls and position/PnL infrastructure. Experience with columnar databases such as ClickHouse.