Senior React Developer

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 benchmarking, and best practice implementation Essential Skills and Experience • 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 Package: • Up to £140,000 (dependent on level of experience) • Up to 20% bonus • Excellent corporate benefits • On-site (Central London)