Senior UI Engineer

Senior UI Engineer - £120,000 – On-site (Central London) Overview We are hiring a Senior UI 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.Key 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

Skills and Experience Required

• Degree in Computer Science, Engineering, or a related field
• 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

Nice to Have

• Experience deploying apps to the Apple App Store
• Knowledge of web security best practices and cyber threat mitigation
• Familiarity with microservices and REST API architecture
• Exposure to Infrastructure as Code tools (e.g. Terraform)
• Experience working with real-time trading or data visualisation platforms

Package:

• Up to £120,000
• Up to 20% bonus
• Excellent corporate benefits
• On-site (Central London)