Prompting & AI Agent Research Engineer

About the Role

Hello Patient is seeking a Prompting & AI Agent Research Engineer to bring structure and rigor to how we advance our AI. We build Mia, an AI voice agent that handles inbound patient calls for multi-location healthcare providers - and as we grow, we need someone who can help us make more confident, evidence-backed decisions about how Mia evolves. You'll design experiments we can trust, stay close to what's emerging in the research community, and turn promising ideas into something testable.

This role sits at the intersection of prompt engineering and applied AI research. You should be comfortable enough technically to prototype and run local experiments independently. Above all, we're looking for someone with deep, hands‑on prompting experience - someone who has deliberately engineered prompts to change how a system behaves.

• Design structured experiments with real controls and statistical rigor

• Build regression test coverage so we know when a global prompt change is breaking things across workflows we didn’t expect

• Create a pipeline of validated, high‑confidence improvements engineering can pull from instead of building on faith

• Work with the team to prioritize what actually gets shipped based on what the experiments say

• Own prompt design across Mia’s agent workflows - multi‑turn, voice‑first, healthcare context

• Stay current on what’s coming out in prompting research, and agent architecture, and bring back ideas worth testing

• Prototype new approaches locally before anything touches production

• Be the person the Product team comes to when they’re stuck on a prompting problem

• Work closely with our Product and Engineering teams - understand where Mia is struggling and help decide what’s worth experimenting on

• Translate experiment results into clear recommendations people can actually act on

• Build out evaluation templates and frameworks so this doesn’t live only in your head

• 5+ years of experience in a prompting, AI research, or applied AI role

• Advanced degree in a research‑oriented field (PhD preferred) - CS, linguistics, cognitive science, stats, or similar

• Real prompt engineering experience - deliberately designing, testing, and improving prompts to change system behavior

• Solid experimental design fundamentals: controls, statistical significance, knowing when a result actually means something

• Hands‑on experience working with LLMs in applied contexts

• Comfort with RAG, agentic architectures, and modern LLM tooling

• Ability to evaluate and validate AI system behavior - understanding what the model is doing and why

• Clear written communication; your findings need to land with engineers and non‑technical stakeholders alike

• Experience with voice AI or conversational systems

• Research background with a focus on prompting techniques, prompt optimization, or evaluation of LLM behavior

• Time at an AI lab, applied AI team, or early‑stage startup

• Familiarity with LLM evaluation frameworks and behavioral test suites

• Published or applied work in prompt design, chain‑of‑thought, or related areas

Base salary: $180,000 - $230,000

Equity: Meaningful ownership in a fast‑growing healthtech startup

Hello Patient is transforming healthcare communication through advanced conversational AI. Our founding team spent 3.5 years scaling Carbon Health’s technology during hypergrowth, where we saw firsthand how much clinical time gets wasted on basic communication—great clinicians buried in admin work, patients stuck in phone tag.

Our AI platform proactively engages patients through perfectly timed calls and texts, resolving complex interactions end‑to‑end—from scheduling to billing to retention. Built with security and compliance at its core, our technology integrates with existing healthcare infrastructure to deliver 24/7 patient engagement.

Backed by Scale and 8VC, we’re building the future of healthcare communication, one conversation at a time.