Senior React Developer - £120,000 - £140,000 – On-site (Central London) Overview We are hiring a Senior React Engineer to join a high-performance technology team within a leading financial services organisation operating in the oil and energy derivatives space. The business runs a cutting-edge electronic trading platform that serves both internal trading teams and external clients, offering low-latency, highly reliable trading access via a modern UI. We are looking for a self-starter who takes ownership of technical challenges and delivers robust solutions, with the ability to work under pressure in a fast-moving trading environment. You must also be a collaborative team player who communicates clearly and contributes to a high-quality engineering culture. Role & Responsibilities Design, build, and maintain a React/TypeScript trading UI, delivering real-time streaming data and a seamless user experience Integrate the UI with RESTful and streaming APIs (built in Rust and Python) Own performance improvements across dashboards, widgets, and live data visualisation Collaborate with QA and DevOps to enhance automated testing and deployment pipelines Lead efforts in securing, scaling, and monitoring the frontend environment Use observability tools (Prometheus, Grafana, Loki) to monitor UI health and performance Drive UI architectural decisions, performance bench-marking, and best practice implementation Esse...