Senior Frontend Engineer (Contractor) in Châtenay-en-France, Île-de-France at Jobgether

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Frontend Engineer (Contractor) based in France.

This fully remote contract opportunity is designed for an experienced frontend engineer who thrives in fast-paced product environments and enjoys building high-quality web applications from the ground up. You will play a key role in delivering intuitive, production-ready user interfaces while collaborating closely with product, design, and backend engineering teams. Working in an AI-assisted development environment, you will leverage modern engineering tools to accelerate delivery while maintaining exceptional standards for code quality, performance, and usability. This role offers significant ownership across the entire feature lifecycle, enabling you to influence frontend architecture, improve engineering practices, and contribute to a rapidly evolving SaaS platform.

• Design, develop, and deliver responsive, pixel-perfect user interfaces using React, TypeScript, and Material UI.
• Own frontend features from design handoff through implementation, testing, deployment, and continuous improvement.
• Build complex, validated forms and deliver seamless user experiences across desktop, tablet, and mobile devices.
• Develop and maintain automated unit, integration, and end-to-end tests to ensure application reliability.
• Optimize frontend performance, accessibility, responsiveness, and Core Web Vitals.
• Collaborate closely with product managers, designers, and backend engineers to deliver high-quality features.
• Participate in code reviews, mentor other engineers, and contribute to frontend best practices and architecture decisions.
• Utilize AI-assisted development tools responsibly to improve productivity while reviewing and validating generated code.
• Help evolve the frontend technology stack, component library, design system, and TypeScript adoption.

• Minimum 5 years of professional experience building production-grade React applications.
• Strong expertise in TypeScript, React, Material UI (v5+), Redux Toolkit, and RTK Query.
• Advanced knowledge of modern CSS, including Flexbox, Grid, responsive design, and mobile-first development principles.
• Experience developing complex forms with React Hook Form.
• Proven experience with frontend testing using Jest, React Testing Library, Cypress, Playwright, or similar frameworks.
• Strong understanding of performance optimization techniques, including lazy loading, code splitting, and application profiling.
• Experience working from Figma designs and delivering pixel-perfect implementations.
• Familiarity with Agile development practices, Git-based workflows, and modern frontend build tools such as Vite or Webpack.
• Comfortable using AI-assisted development tools such as Claude, Claude Code, Cursor, or GitHub Copilot within daily engineering workflows.
• Excellent written English communication skills and the ability to work independently in a remote, asynchronous environment.
• Availability to consistently overlap with U.S. business hours.
• Experience with Firebase, GraphQL, REST APIs, mapping libraries, micro-frontends, or B2B SaaS products is considered an advantage.

• Fully remote contractor opportunity based in Europe.
• High level of ownership with end-to-end responsibility for frontend feature development.
• Opportunity to work on a modern SaaS platform serving mission-critical business operations.
• Collaborative environment with close interaction across engineering, product, and design teams.
• AI-first engineering culture leveraging cutting-edge development tools.
• Opportunity to influence frontend architecture, engineering standards, and design systems.
• Flexible remote work within a distributed international team.
• Exposure to challenging technical projects with opportunities for continuous professional growth.