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 quality, usability, and engineering excellence.

Full Stack Ownership

• Own complex features end-to-end, from user interface development through backend services and APIs.
• Collaborate closely with product, design, and data teams to transform ideas into exceptional customer experiences.
• Design and implement scalable APIs and services that power our member-facing applications.
• Contribute to technical decisions across frontend, backend, infrastructure, and data systems.

User Experience & Performance

• Champion frontend performance, responsiveness, accessibility, and reliability.
• Optimize application performance across web and mobile platforms.
• Leverage analytics and user feedback to continuously improve product experiences.
• Ensure members can easily understand and interact with complex health information.

Technical Leadership

• Provide architectural guidance and technical mentorship across the engineering organization.
• Lead high-impact initiatives from concept through launch.
• Drive engineering standards, code quality, and best practices.
• Help scale engineering processes and systems to support rapid company growth.

Innovation & Collaboration

• Partner with Product, Design, Clinical, and Data teams to deliver impactful features.
• Evaluate emerging technologies and development approaches to improve product quality and team velocity.
• Foster a culture of continuous improvement, experimentation, and learning.

Qualifications & Skills

Required Experience

• 10+ years of software engineering experience, including significant experience building customer-facing products.
• Proven success leading complex technical initiatives in high-growth or startup environments.
• Experience balancing hands-on development with technical leadership and mentorship.

Frontend Expertise

• Deep expertise in JavaScript/TypeScript and modern frontend development.
• Extensive experience with React and modern frontend architectures.
• Strong understanding of:
• Design systems
• Component libraries
• State management
• Accessibility (WCAG)
• Performance optimization
• Frontend testing frameworks
• Modern build and deployment tooling
• Experience building highly interactive, data-rich user interfaces.

Mobile Development

• Understanding of mobile architecture, performance optimization, and platform-specific considerations.

Full Stack Development

• Experience designing and building APIs and backend services.
• Strong proficiency with Python or similar backend technologies.
• Ability to comfortably work across the entire application stack.
• Experience integrating third-party services and external data platforms.

Product & User-Centric Thinking

• Strong product instincts and a passion for creating exceptional user experiences.
• Ability to balance technical excellence with business impact.
• Experience collaborating closely with Product and Design teams.

Engineering Excellence

• Strong understanding of:
• Agile development methodologies
• Test-driven development
• Continuous integration and deployment
• Software architecture principles
• Scalable system design
• Commitment to writing maintainable, high-quality code.

Nice-to-Have Skills & Experience

• Advanced expertise with React, React Native, and TypeScript.
• Experience building large-scale consumer applications.
• Experience developing data visualization and analytics experiences.
• Familiarity with GCP, Postgres, and modern web architecture patterns.
• Experience integrating AI or machine learning capabilities into user-facing products.
• Startup experience as an early engineering hire, founder, or technical leader.

Key Projects and Initiatives

As a vital member of our team, you will have the opportunity to engage with or lead a variety of groundbreaking projects. These initiatives are designed not only to challenge your skills but also to make a significant impact on the field of health technology.

Among These

• AI-Powered Health Analysis Tools: Take the helm or contribute to the development of cutting-edge AI-powered tools designed to analyze health data. These projects aim to unlock new insights into health and wellness, offering personalized recommendations and predictions to our users. Your work will involve optimizing algorithms, refining data models, and ensuring these tools are both accurate and scalable.
• Enhancing Data Integration: You will play a crucial role in enhancing the integration of diverse data sources with our platform. This initiative is critical to providing a holistic view of our users' health, incorporating data from wearable technologies, medical records, and other relevant sources. Your expertise will be essential in ensuring seamless, secure, and efficient data flow across systems, enriching our platform's capability to deliver comprehensive health insights.

These projects represent just a glimpse of the exciting, impactful work you'll be involved in at our company. Your contributions will directly influence the evolution of our platform, empowering individuals to take control of their health in innovative ways. We're looking for a candidate who is eager to dive into these challenges and push the boundaries of what's possible in health technology.

To be a strong fit, you embody our Core Values

• Ruthless Prioritization:

• We don’t let perfect get in the way of progress.

• We move quickly to drive value, not perfection.

• We prioritize what drives impact.

• We never compromise on standards of excellence.

• Member-First, Always:

• We design and deliver like we’re caring for someone we love.

• We create calendar, actionable, human experience.

• We prioritize responsiveness, peace of mind, and outcomes.

• We empower members with truth, clarity, and care.

• One Team, Moving Fast:

• We are aligned in purpose, prioritization, and speed.

• We gather diverse perspectives to make informed decisions.

• We clear paths for each other and move fast together.

• We communicate clearly and respectfully, rallying around shared goals.

• Radical Ownership, Relentless Execution:

• We don’t just ship– we own outcomes and drive results.

• We act with urgency and precision

• We anticipate, initiate, and follow through.

• We meet challenges with grit and pragmatism.

• We embrace new tech to deliver better outcomes.

• Mission Over Ego:

• We are ruthlessly aligned to our mission - and leave ego at the door.

• We disagree and commit.

• We don't tolerate politics or withholding information.

• We operate with honesty, transparency, and respect.

• Sustained Integrity in Every Detail:

• We earn trust by obsessing over accuracy, quality, and clarity in everything we do.

• We prioritize clinical precision - data must be right.

• We sweat the details because outcomes depend on them.

Why You'll Love Working With Us

We value our team at Function and offer a competitive salary and benefits package, flexible working hours, and a dynamic work environment where creativity and innovation are encouraged. If you are a highly motivated and experienced individual who is passionate about using technology to improve people’s lives, we would love to hear from you.

At Function, we celebrate diversity and are committed to building a diverse and inclusive workforce. As an equal opportunity employer, we do not discriminate on the basis of race, color, gender identity, ancestry, religion, age, sexual orientation, national origin, disability, marital status, Veteran status, or any other occupationally irrelevant criteria.

Join the Function Health team and become a part of our mission to build a healthier future for all. Discover more about us and how we're changing the face of healthcare at Function Health.

Important Notice: Legitimate communication from the Function Health team will always come from an email address ending in @functionhealth.com. Function Health will never request personal information such as banking details or payment during the hiring process. Please be cautious of communications or job offers that come from other email domains, instant messaging platforms, or unsolicited calls. If you ever have doubts about the legitimacy of a communication, please reach out to us directly at talent@functionhealth.com.