Our client, a leader in mobile payment systems, is seeking a Senior Fullstack Frontend Engineer to own and solve complex frontend challenges in connected payments. You will contribute to a major payments platform used by over 27 million monthly active users and supporting $100 billion in transaction volume, ensuring reliability, performance, and quality across the web experience.
This role is an opportunity to take technical ownership of mission-critical frontend systems, work across the full stack with Node.js/Express when needed, and improve testing and observability practices using Jest and React Testing Library.
Responsibilities
- Design and develop React-based web applications and UI components for a high-scale payments platform
- Build and maintain unit and functional tests using Jest and React Testing Library
- Debug client-side issues and trace problems across the web application stack, including server-side Node.js/Express logs
- Diagnose and resolve production issues, contributing to release support and incident response
- Collaborate with engineers and QA to ensure code quality, test coverage, and reliable deployments
- Review and improve frontend architecture and testing practices
- Implement cross-browser compatible solutions and optimize for consistent user experience
- Contribute to backend endpoints and integrations as needed using Node.js and Express
Requirements
- 5+ years of professional JavaScript experience
- 3+ years of professional React experience
- Proficiency writing unit and functional tests with Jest and React Testing Library
- Practical experience with Node.js and Express and a basic fullstack understanding
- Strong debugging skills and ability to trace issues across client and server logs
- Experience contributing independently to production React applications
- Ability to collaborate effectively with engineering teams for QA and release support
- Solid understanding of testing practices and maintaining test coverage
Nice-to-Have Skills
- Experience ensuring cross-browser compatibility
- Strong CSS skills
- Familiarity with React Hooks
- Experience with Apollo GraphQL
