Fullstack Engineer (Java /C++) in London

This Full Stack Engineer role in London is onsite three days per week, embedded in the heart of high-frequency trading environments. You shape the backbone of real-time market data distribution, collaborating with quantitative, trading, and engineering teams to push the limits of speed and reliability. The market rewards those who build platforms that never miss a tick. Responsibilities * Design, develop, and maintain high-performance, ultra-low-latency software applications and market data distribution systems * Build, tune, and support low-latency network programming solutions and kernel bypass architectures on Linux environments * Develop and enhance high-throughput, low-latency components using Core Java and C++ * Manage deployments, tooling, and infrastructure automation using internal and enterprise deployment pipelines (including UBS Bluezone and UBSDeploy) * Integrate, optimize, and distribute real-time market data across over 70 proprietary direct feeds in EMEA, US Options, and MIFID II market structures * Collaborate with cross-functional quantitative, trading, and engineering teams to deliver extremely reliable, fault-tolerant, and sub-microsecond resilient systems * Perform rigorous performance analysis, latency troubleshooting, and system tuning of applications, network stacks, and market data distribution protocols (Denali, MPAC, Beacon, Refinitiv ETA) * Support knowledge transfer and handover activities as part of project onboarding and cross-team enablement Requirements * 5–10 years of software engineering experience in high-frequency trading (HFT), financial markets, or ultra-low-latency environments * Strong hands-on development expertise with Core Java and C++ * Deep expertise in Linux systems, kernel bypass low-latency tuning, and low-latency network programming * Expert knowledge of market data distribution protocols, including Refinitiv ETA, Denali, MPAC, and Beacon * Comprehensive domain knowledge across EMEA, US Options, and MIFID II market structures, alongside experience with over 70 proprietary direct feeds * Experience with deployment and management tools such as client Bluezone and client Deploy * Strong performance tuning, profiling, and network/application troubleshooting skills * Excellent problem-solving, analytical, and communication abilities Nice to Have * Entrepreneurial mindset with a proactive, ownership-driven approach in high-pressure trading floors * Experience in event-driven architecture, distributed systems, and hardware-software co-design * Knowledge of CI/CD practices, automated testing, and DevOps automation tailored for low-latency builds * Experience working in large-scale enterprise financial environments and electronic trading desks * Familiarity with advanced monitoring, hardware timestamping, and network telemetry tools