Founding Engineer, Applied Research (US)

We are looking for a Research Engineer with 3+ years of experience to advance the core clinical intelligence capabilities of our product. You'll take ambiguous research problems in healthcare AI, bound them, solve them, and deploy them into production: working across evals, model fine-tuning, agentic systems, and browser/computer use models. This is an applied research role at a seed-stage company backed by a16z and Lightspeed that is building the clinical AI layer for healthcare payments. If you're excited about making models drive real-world impact in an industry that desperately needs innovation, this is the place to do it.

What will you be doing?

• Building clinical evals to measure and improve model performance across chart understanding, claims review, authorization logic, denial analysis, and payer policy interpretation

• Improving Backbone's core intelligence through prompting, fine-tuning, retrieval, structured reasoning, and evaluation of language models on real clinical and financial data

• Building and improving agentic browser-use and computer-use models to navigate payer portals, EHRs, and complex healthcare software

• Translating product feedback from live provider and payer workflows into bounded research problems, then deploying solutions into production

• Partnering with backend and forward-deployed engineers to productionize research improvements at high velocity