Full-Stack AI Engineer in Cambridge

Liza Health is a Cambridge-based startup building an AI-enabled platform for modern primary care. Our bet is simple: primary care is the foundation of a healthy US health system, and AI finally makes it possible to rebuild and scale primary care from first principles instead of patching what's broken. Liza was co-founded by Dr. Rushika Fernandopulle, a practicing physician who previously co-founded Iora Health, the relationship-based primary care company later acquired by One Medical and then Amazon, serial tech entrepreneur and investor Andy Palmer and healthcare serial entrepreneur Duncan Reece. We bring decades of experience redesigning care delivery together with a team that builds with frontier AI every day.

We work alongside primary care practices to change how care is delivered: more time for relationships, less time on administrative burden, and patients who get the right care at the right time. If you want your engineering work to make care better for real patients and clinicians, this is the place.

The role involves designing, building and shipping the AI systems at the core of Liza's care model. You'll own problems end to end: sitting with clinicians and care teams to build real-world healthcare applications for patients, clinicians and clinical operators. This is a generalist role by design. On any given week you might write a prompt and its eval suite, wire an agent into an EHR via FHIR, build a frontend feature for care coordinators, and develop healthcare data pipelines. We value curiosity, learning fast and shipping well. We don't care much about titles or hierarchy.

The AI engineering bar here is the one set at the top AI labs: we A/B-test agent changes in a harness, LLM judges score replies in production, and we review production traces every week. The difference is where the work lands: in the hands of patients and primary care teams across the US, helping real people live healthier lives while reducing overall healthcare costs.

What you'll do:

• Build production AI applications and agentic systems that support patients, clinicians and care teams across scheduling, intake, documentation, care coordination, outreach and clinical decision support.
• Partner directly with patients, physicians, health coaches and operations staff to turn messy, real-world workflows into clear technical requirements and measurable outcomes.
• Work closely with our AI-native design team to create experiences that are simple, efficient and effective for all of our users.
• Design, test and iterate on prompts, context and tool definitions that shape how our models behave, and keep them versioned, reviewed and safe to change.
• Define and run evaluations: build gold-standard datasets with clinicians, write rubrics and automated graders, read transcripts for what the metrics miss, and set launch criteria before anything reaches a patient.
• Integrate AI with our healthcare stack: our FHIR backend (Medplum), practice EHRs, HIE aggregators such as Metriport, HL7 interfaces, claims and scheduling systems, and our data platform.
• Build with PHI, HIPAA, privacy, security and auditability in mind, including human-review workflows and clear escalation paths for clinical risk.
• Monitor systems in production and use error analysis, observability and user feedback to rapidly improve reliability, cost, latency and model selection.
• Turn what we learn into reusable building blocks: shared eval harnesses, agent patterns, integration libraries and internal tools that make the whole team faster.

Who we're looking for:

• A mission-driven believer. You think US healthcare can be dramatically better, that primary care is where that change starts, and that AI is the lever that makes it possible now.
• A generalist. You're comfortable across the stack and across problem types, from backend services and data pipelines to frontends, prompts and evals.
• An exceptional builder. You take pride in shipping things people actually use at large scale and you have a track record of doing it.
• A strong teammate. You do your best work on small, cross-functional teams with clinicians, designers, operators and other engineers.
• Someone who has fun. You bring curiosity, humor and energy to hard problems.
• Someone comfortable with ambiguity. You can frame an unclear problem, make good calls with incomplete information, and own the outcome.

No prior healthcare experience or clinical credentials are required. We'll teach you the domain; we're hiring for curiosity, judgment, craft and heart.

Essential AI skills:

• Production LLM application engineering. 5+ years of software engineering (our stack is TypeScript end to end), with hands-on experience shipping LLM-powered products to real users at scale.
• Prompt and context engineering. Designing, testing and optimizing system prompts, tool descriptions and retrieved context.
• Agents and tool use. Building agentic workflows with function calling, multi-step planning, memory and state management.
• Evaluation and error analysis. Building datasets and rubrics with domain experts, LLM-as-a-judge and automated graders.
• Retrieval and knowledge systems. RAG pipelines, embeddings, structured knowledge and memory.
• Full-stack and systems breadth. APIs, data infrastructure, web and mobile frontends, cloud deployment, CI/CD, containers and production observability.
• AI-native development. Fluency with coding agents and AI-assisted workflows.

Like to have:

• Experience with EHR and interoperability technologies such as Epic, Oracle Health (Cerner), athenahealth, HL7, FHIR.
• Exposure to primary care, value-based care, care coordination or patient access workflows.
• Experience fine-tuning or post-training models.
• Voice or multimodal AI experience.
• Prior work as a forward-deployed engineer, technical founder or early engineer at a startup.
• Open-source contributions, publications or side projects that show your craft.

How we work and what we offer:

• Small, cross-functional teams. Engineers, clinicians, designers and operators work side by side.
• One codebase, shared by everyone. Our APIs, web and mobile apps, infrastructure and agents live in one TypeScript monorepo.
• Speed with rigor. We prototype fast, test with real users early, and hold a high bar for safety and quality.
• Fun is part of the job. Expect team lunches, hack days, celebrating wins together.

Location: Cambridge, MA, with in-person collaboration. Hybrid encouraged - most people are in the office 2-3 days/week but we are flexible especially after ramp up.

Compensation: Competitive salary and meaningful equity, plus comprehensive health, dental and vision benefits.

Liza is an equal opportunity employer. We value diverse perspectives and backgrounds, which make us better at building care for everyone.