Staff Software Engineer (Frontend / UI)

Company Overview Function Health is the AI operating system for health, designed to empower people to live 100 healthy years. We are redefining how individuals understand, measure, and improve their health by moving beyond the limitations of traditional care and enabling comprehensive, continuous insight into human biology. Function has been recognized as one of Fast Company’s Most Innovative Companies of 2024 , and is venture-backed by Redpoint and other leading venture firms. Over half a million members have joined Function to take control of their health. Through comprehensive lab testing, MRI and CT imaging, longitudinal data, and guidance from AI and clinical teams, Function gives members a complete and continuous view of their health — and the clarity to act on it. Through acquisitions across imaging, mobile phlebotomy, and supplement tracking and optimization, Function is building an integrated health platform that spans the full path from testing to health clarity to daily action. Function recently announced a $298M Series B and is entering its next chapter of growth. As we scale, the quality and durability of our People systems, data, and insights will directly shape our ability to attract, retain, and support exceptional talent. We are growing our team and seeking out world-class talent that deeply believes in our mission to positively impact global health, has a relentless bias toward action, and a growth mindset. Function fosters a collaborative and dynamic environment where every day we build the future. Role We are seeking a highly skilled and product-minded Staff Software Engineer to join our team at Function. In this role, you will lead the development of the member-facing experiences that help people understand and act on their health data. You will be responsible for shaping the architecture, performance, and usability of our web and mobile applications while contributing across the full stack. The ideal candidate is an experienced engineer with deep frontend expertise, strong product instincts, and a passion for building elegant user experiences. You care deeply about performance, usability, accessibility, and design quality, while also being comfortable building APIs, backend services, and scalable systems when needed. As a key member of our engineering team, you will help define how millions of users interact with their health information and drive technical decisions that shape the future of Function’s products. Key Responsibilities Frontend & Product Development Leadership Lead the architecture, design, and development of modern web and mobile applications. Build intuitive, performant, and highly polished user experiences using React and React Native. Establish frontend best practices around component architecture, state management, testing, accessibility, and performance. Drive the evolution of our design system and shared UI component libraries. Maintain a high bar for product…