Senior React Engineer

IntecSelect; Greater London; On-site; GBP 125,000 - 150,000; Full time

Job summary

A leading financial services organisation is seeking a Senior React Engineer to join their Central London team. This role involves designing and maintaining a React/TypeScript trading UI, with responsibilities including performance improvements and API integrations. The ideal candidate will have over 5 years of Front End/UI engineering experience and expertise in React and TypeScript. The contract lasts 6 months with a high possibility of extension, offering up to £800 per day based on experience.

Qualifications

• 5+ years of experience in Front End/UI engineering with a focus on performance and scale.
• Deep expertise in React, TypeScript, and JavaScript.
• Strong understanding of WebSocket integration and low-latency data streaming.

Responsibilities

• Design, build, and maintain a React/TypeScript trading UI.
• Integrate the UI with RESTful and streaming APIs.
• Own performance improvements across dashboards and live data visualisation.
• Collaborate with QA and DevOps to enhance testing and deployment pipelines.

Skills

React

TypeScript

JavaScript

WebSocket integration

low-latency data streaming

Git

Education

Degree in Computer Science, Engineering, or a related field

Tools

Redis

Kafka

Azure

AWS

Prometheus

Grafana

Loki

Job description

Senior React Engineer - £700 - £800 p/day - On-site (Central London)

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 Front End 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

• Degree in Computer Science, Engineering, or a related field
• 5+ years of experience in Front End/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 (eg Google PageSpeed Insights) and responsive UI optimisation

Desirable Skills and Experience

• 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 (eg Terraform)
• Experience working with Real Time trading or data visualisation platforms

Package

• Initial 6 month contract (high possibility of extension)
• Up to £800 p/day (dependent on level of experience)
• On-site (Central London)