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
Experience ensuring cross-browser compatibility
Strong CSS skills
Familiarity with React Hooks
Experience with Apollo GraphQL
