Senior Frontend Product Engineer — React, React Native & TypeScript

We are looking for a senior frontend product engineer to help improve and expand a production healthcare SaaS platform used by emergency medical service organizations. This is not a simple website or greenfield project. We have an established application with real users, complex operational workflows, and both web and mobile experiences. Our frontend stack includes: - React - React Native - TypeScript - REST APIs and real-time application features - GitHub Actions and automated testing - AWS-hosted backend services THE ROLE You will take ownership of frontend product quality across our web and mobile applications. Your job is to turn requirements and working functionality into interfaces that are polished, intuitive, responsive, accessible, and dependable. You will work with the product owner, AI development tools, and a senior backend/database engineer. The backend engineer will own database reliability and API implementation. You will own how users experience the product. WHAT YOU WILL DO - Build and improve React web interfaces - Build and improve React Native mobile workflows - Turn rough screens and prototypes into polished production experiences - Simplify complicated healthcare and operational workflows - Integrate frontend features with existing APIs - Establish clear API requirements with the backend engineer - Improve responsive behavior across screen sizes - Create reusable components and consistent interaction patterns - Improve loading, empty, error, and success states - Strengthen form validation and prevent user mistakes - Improve accessibility, keyboard navigation, and usability - Diagnose frontend performance and state-management problems - Add meaningful component, integration, and end-to-end tests - Review AI-generated frontend code before it reaches production - Document important components and frontend conventions HOW WE WORK The product owner uses AI tools extensively for product research, requirements, prototypes, investigation, and initial implementation. Your role is not simply to reproduce screenshots or complete isolated tickets. We need someone who can: - Understand the user’s actual workflow before changing the interface - Critically review AI-generated code and designs - Recognize usability problems that automated tools may miss - Turn incomplete prototypes into maintainable production features - Make good design decisions without requiring perfect specifications - Test the complete user experience, including uncommon and failure states - Communicate clearly with a non-technical product owner - Coordinate effectively with the backend engineer We value thoughtful product judgment. You should be comfortable explaining when a proposed interface is confusing, unsafe, or unnecessarily complicated. REQUIRED EXPERIENCE - Strong production experience with React and TypeScript - Experience building complex business applications—not only marketing websites - Strong responsive-design and CSS skills - API integration, asynchronous state, forms, and validation - Reusable component architecture - Frontend performance and debugging - Automated frontend testing - Git and pull-request-based development - Strong written and spoken English - At least 2–3 hours of reliable overlap with US Eastern Time STRONG ADVANTAGES - React Native production experience - Healthcare, insurance, billing, logistics, or other workflow-heavy software - Accessibility experience - Real-time interfaces, notifications, maps, or operational dashboards - Design-system or component-library experience - Experience working successfully with AI-assisted development - Experience collaborating with a separate backend engineer ENGAGEMENT DETAILS - Long-term hourly engagement - Approximately 10–20 hours per week initially - Opportunity to expand as the frontend workstream grows - Paid, clearly scoped trial project - Individual freelancers preferred - You must personally perform the work - No undisclosed subcontractors or shared access TO APPLY Please answer the following questions in your proposal: 1. Share an example of a complex React application you personally built. What parts did you own? 2. Describe a confusing or inefficient workflow you redesigned. What did you change, and how did you determine it was better? 3. How do you handle loading, empty, error, offline, permission-denied, and partial-success states? 4. What frontend tests do you consider essential before releasing a feature? 5. Describe your production experience with React Native. If React Native is not one of your strengths, say so directly. 6. How have you used AI development tools, and how do you verify that AI-generated frontend code is correct and maintainable? 7. What hours can you reliably overlap with US Eastern Time? 8. Will you personally perform all work and be the only person accessing our code and systems? Please include links to relevant applications, code samples, or portfolio work. Explain specifically what you personally contributed to each example. Generic proposals that do not answer these questions will not be considered.