AI/Machine Learning Engineer

Citizen Health was founded on the belief — shaped by firsthand lived experiences navigating healthcare — that having the right advocate is the single most important factor in achieving better care and outcomes. By uniquely combining data, AI, and community, Citizen is building a personalized AI advocate powered by patients' complete medical histories and data from thousands of other patients to generate personalized insights for clinical decisions and day-to-day challenges. Starting in rare and complex conditions, patients share their data in exchange for value, enabling biopharma and researchers with seamless access to patients and regulatory-grade data, shaving years off drug development for much-needed treatments.
Citizen is founded by experienced entrepreneurs with multiple successes under their belts and is funded by top-tier investors including 8VC, Transformation Capital, and Headline Ventures, among others. We are a mission-driven team excited to be building the future of consumer healthcare.

Citizen Health is seeking AI/Machine Learning Engineers to lead the development and deployment of cutting-edge AI solutions that power our patient-centric platform. This role is crucial in designing and implementing sophisticated machine learning models that transform complex health data into actionable insights for patients, healthcare providers, and researchers.

As a key technical leader, you'll be at the forefront of applying advanced machine learning techniques to solve challenging problems in rare disease research and patient care. Your work will be instrumental in developing AI-driven solutions that improve disease understanding, treatment recommendations, and patient outcomes.

• Design and implement end-to-end machine learning solutions, from data preprocessing to model deployment and monitoring

• Develop and optimize agentic Large Language Models (LLMs) solutions for healthcare applications using techniques like fine-tuning and Retrieval-Augmented Generation (RAG)

• Create robust data pipelines for validation, and deployment

• Implement ML systems that can effectively process and analyze diverse healthcare data types, including structured clinical data, medical imaging, and unstructured text

• Collaborate with backend engineers to integrate ML models into our production infrastructure

• Ensure ML systems meet strict healthcare compliance requirements while maintaining high performance

• Design and implement monitoring systems for model performance, data drift, and system health

• Lead research initiatives to explore and implement state-of-the-art AI/ML techniques

• Collaborate with clinical experts to validate model outputs and ensure medical accuracy

• Stay current with the latest developments in AI/ML, particularly in healthcare applications

You are a builder and problem solver at heart who loves working in fast-paced, innovative environments. You have experience working in consumer technology companies and have also worked on products that deal with complex data and systems. You love start-ups and can operate autonomously knowing that collaboration is the key to your success.

• 5+ years of experience in machine learning engineering, with a focus on production ML systems

• Strong proficiency in Python and AI/LLM frameworks (LangChain, LangGraph, AutoGen, CrewAI)

• Experience designing and implementing production-grade ML pipelines

• Proven track record of deploying ML/LLM solutions in production environments

• Strong understanding of ML fundamentals, including deep learning, NLP, and statistical modeling

• Experience with ML ops tools and best practices

• Proficiency in working with large-scale datasets and distributed computing

• Strong software engineering skills and coding best practices

• Degree in Computer Science or equivalent degree

• Hands-on experience integrating and optimizing Large Language Models (LLMs) in production environments

• Proficiency with LLM tools and techniques such as LangChain, LlamaIndex, Prompt Engineering

• Experience implementing Retrieval-Augmented Generation (RAG) systems

• Familiarity with vector databases and efficient similarity search techniques for AI applications

• Experience with message queuing systems and data streaming platforms

• Familiarity with data processing and analytics technologies

• Proven track record of high-quality coding and architectural design

• Passion for creating robust, scalable, AI-driven systems that make a real-world impact in healthcare

At Citizen Health, you will be part of an ambitious mission to build innovative AI-driven solutions that redefine the consumer healthcare experience and improve outcomes for millions. We value curiosity, creativity, and collaboration, and we believe in empowering every team member to have an impact. Here, you’ll find:

• The chance to work on pioneering AI technologies and solve complex problems that push the boundaries of what’s possible in healthcare

• The freedom to lead your projects and shape the company’s direction in a mission-driven environment where your work makes a real impact

• A fast-paced, high-growth setting that brings expanding opportunities and clear paths for career progression

• A supportive culture of learning, experimentation, and innovation, where new ideas are encouraged and explored

• A commitment to empathy and diversity, recognizing that our greatest strengths come from our varied perspectives and experiences

• Regular team activities and knowledge sharing, all within a culture that prioritizes well-being and connection

• Competitive salary + equity package

• Comprehensive health, dental, and vision insurance

• Unlimited paid time off, including a generous parental leave

• Flexible hybrid work environment

Our Commitment to Diversity & Inclusion: Citizen Health is proud to be an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We welcome applicants of all backgrounds, identities, and experiences. Everyone deserves an equal chance to contribute and grow here — regardless of race, gender identity, sexual orientation, religion, national origin, age, disability, or veteran status.

Don't meet every qualification? No worries! We believe that passion, curiosity, and the right mindset are just as important as a checklist of skills. If you’re excited about what we’re building, we encourage you to apply.