Founding Research Engineer - AI Health Assistant

Lotus AI; San Francisco (CA); On-site; USD 180,000 - 280,000; Full time

Job summary

Lotus Health is hiring a Founding Research Engineer in San Francisco to design and ship core reasoning and agentic systems for patient care. You will curate medical data, train and evaluate models, and build retrieval and tool-use components with safety and citations.

You will collaborate with clinicians and founders to turn breakthroughs into production features that patients and clinicians can trust, with on-site work in SF and a focus on practical impact.

Qualifications

• Strong Python and deep experience with PyTorch or JAX.
• Track record shipping applied ML or LLM features to real users.
• Hands-on experience with RAG, prompt and tool design, evaluation harnesses, and error analysis.
• Solid SQL plus comfort with vector stores and retrieval patterns.
• Product sense, pragmatism, and the ability to reduce complex systems into simple, reliable components.
• Willingness to work on-site in San Francisco.

Responsibilities

• Research and Modeling: build agentic workflows with retrieval, function calling, and planning to answer health questions with citations.
• Datasets and Labeling: curate deidentified datasets from EHR, claims, labs, devices, and chats.
• Evaluation and Safety: own the eval stack for medical correctness, bias, safety, latency and cost.
• Systems and Production: ship research to production with observability, feature flags and rollback plans.

Skills

Python

PyTorch

JAX

RAG

Prompt design

Eval harnesses

SQL

Vector stores

Retrieval patterns

Product sense

On-site

San Francisco

Tools

Docker

ECS

Langfuse

Observability stacks

Job description

Lotus Health is hiring a Founding Research Engineer in San Francisco to design and ship core reasoning and agentic systems for patient care. You will curate medical data, train and evaluate models, and build retrieval and tool-use components with safety and citations.

You will collaborate with clinicians and founders to turn breakthroughs into production features that patients and clinicians can trust, with on-site work in SF and a focus on practical impact.