JavaScript Engineer (React.js) – Full‑time

About the role

A UK‑based client is looking for a highly experienced JavaScript Engineer with deep expertise in React.js to join their engineering team. You will design, build and optimise high‑performance web applications used by thousands of users, while providing technical leadership across the front‑end stack.

Key responsibilities

• Architect, develop and maintain complex React.js applications with clean, scalable and testable code.
• Lead front‑end technical decisions and guide the team in implementing best practices.
• Collaborate with product managers, designers and backend engineers to deliver end‑to‑end solutions.
• Optimise applications for maximum speed, responsiveness and accessibility.
• Drive code reviews, write technical documentation and ensure high engineering standards.
• Mentor junior and mid‑level engineers and contribute to team growth.

Required profile

• 4+ years of professional experience in JavaScript engineering.
• Expert knowledge of React.js, React Hooks and modern front‑end tooling.
• Strong understanding of TypeScript, ES6+, HTML5 and CSS3.
• Experience with state‑management libraries such as Redux, Zustand or Recoil.
• Proficiency with build tools and bundlers like Webpack, Vite or Rollup.

Required skills

• JavaScript
• React.js
• React Hooks
• TypeScript
• HTML5
• CSS3
• Redux / Zustand / Recoil
• Webpack / Vite / Rollup
• Next.js (preferred)
• Jest, React Testing Library, Cypress (preferred)