Salary: £30,500 - 104,500 per year Requirements: 5 years of experience in frontend/UI engineering, with a focus on performance and scale Deep expertise in React, TypeScript, and JavaScript Strong understanding of WebSocket integration, low-latency data streaming, and threading Experience troubleshooting data-heavy UIs and optimising load times Familiarity with tools like Redis, Kafka, and cloud platforms such as Azure or AWS Proficient in Git and modern source control workflows Knowledge of performance diagnostics (e.g. Google PageSpeed Insights) and responsive UI optimisation 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 benchmarking, and best practice implementation Technologies: AWS Azure Cloud DevOps Frontend Git Grafana JavaScript Kafka Prometheus Python React Redis Rust TypeScript UX UI Design More: We are hiring a Senior React Engineer to join our high-performance technology team within a leading financial services organisation operating in the oil and energy derivatives space. Our 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. This role offers a competitive package of up to £140,000, with an up to 20% bonus and excellent corporate benefits, all based in Central London. last updated 7 week of 2026