Principal React Engineer The Opportunity We're partnering with a highly regarded technology organisation delivering enterprise-scale digital platforms used by some of the world's leading brands. They are now seeking a Principal React Engineer to play a key role in modernising and evolving their front-end architecture as part of a major multi-year transformation programme. In this role, you will act as the technical leader in the React space - shaping front-end architecture, improving performance, introducing best-practice engineering standards, and contributing significantly to shared codebases. You'll collaborate closely with product, UX, backend engineering, and data teams to deliver seamless, scalable, customer-facing applications used globally. This is an opportunity to influence technical direction, set standards, and mentor others, while remaining deeply hands-on in building world-class front-end solutions. Key Responsibilities Front-End Engineering & Architecture (80%) Design and evolve front-end architecture for complex, distributed systems. * Ensure UI/UX designs are technically feasible, performant, and accessible. * Implement information architecture and interaction design aligned with backend specifications. * Develop new user-facing features using modern, component-driven development. * Build and maintain internal design systems and reusable component libraries. * Write clean, test-driven, production-quality React and TypeScript code. * Optimise applications for speed, scalability, maintainability, and accessibility. * Contribute regularly to shared codebases with minimal oversight. * Participate in the full software development lifecycle and communicate progress to the Development Director. * Update, maintain, and modernise existing front-end applications. Product Analysis & Support (15%) Work with Customer Support and Implementation teams to resolve issues and bugs. * Support cross-functional teams with technical insights, solutions, and guidance. * Engage with customers and internal teams on technical requirements or project status. Innovation & Continuous Improvement (5%) Stay ahead of front-end trends and emerging technologies. * Contribute ideas to improve processes, tools, and product capabilities. * Identify opportunities to drive innovation across the engineering function. Essential Skills & Experience Bachelor's degree in Computer Science, Engineering, or similar discipline (or equivalent experience). * 5 years' experience building complex front-end applications at scale. * React 18 & TypeScript expertise, including: - Advanced hooks - Strict typing, generics - Composition patterns - Performance optimisation * Experience with: - TanStack Query, Router, Table, Virtual - Vite - React Hook Form & Zod - Nx Workspace - Tailwind CSS - Vitest, Cypress, MSW - Storybook 8 * Strong understanding of component-driven development and design systems. * Knowledge of micro-frontend architecture, Nx monorepos, and domain-driven design. * Experience writing high-quality unit, integration, and functional tests. * Ability to break down complex problems and collaborate with cross-functional teams. * Strong communication, documentation, and mentoring skills. Desirable Skills Experience working with large-scale API-driven platforms. * Understanding of cloud-native architecture (Azure, AWS, or GCP). * Knowledge of CI/CD pipelines and modern DevOps practices. * Exposure to back-end or full-stack environments. * Experience working in fast-moving or customer-facing product environments. Why Join? Play a pivotal role in a major front-end platform modernisation. * Lead technical direction in React while remaining fully hands-on. * Work across enterprise-scale products used globally. * Hybrid working with only 2 days on-site in Belfast. * Exceptional salary package * Strong engineering culture, collaborative environment, and real autonomy. * Opportunities to influence architecture, standards, and front-end strategy. Skills: React Belfast Derry