Principal React Engineer TLNT1_NI in Belfast

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.