Senior React Engineer (contract/freelance)

About the role

We are looking for a Senior React Engineer to join our agile squad in Luxembourg, building high‑impact modern web applications for an international audience. You will own the development of scalable, high‑performance interfaces and collaborate closely with cross‑functional teams.

Key responsibilities

• Develop modern features using JavaScript and React, ensuring performance and scalability.
• Design reusable, maintainable UI components and shape overall UI architecture.
• Participate actively in agile ceremonies such as stand‑ups, planning, and reviews.
• Collaborate with backend engineers, designers, analysts, and product owners to deliver cohesive solutions.
• Maintain technical alignment across the frontend stack, promoting consistency and scalability.

Required profile

• Strong frontend engineering experience focused on UI development.
• Deep expertise in React (hooks, state management) and modern JavaScript.
• Solid understanding of HTML5, CSS3, responsive design and browser performance.
• Familiarity with modern tooling, Git workflows, and package managers.
• Experience consuming REST APIs.
• Fluent English for cross‑team collaboration.

Required skills

• React
• JavaScript (ES6+)
• HTML5
• CSS3
• Git
• Build tools (e.g., Webpack, Vite)
• Package managers (npm, Yarn)
• REST API integration
• Jest, React Testing Library, Cypress (nice to have)
• CI/CD pipelines, Docker (nice to have)
• WCAG accessibility awareness (nice to have)