Principal Engineer (backed by Y Combinator, $5M+ ARR, $23M+ raised)

The posting, as Legion Health wrote it

🧠 ABOUT LEGION HEALTH

At Legion Health https://legionhealth.com/, we believe everyone deserves fast, affordable, and world-class health care, and we’re developing the AI infrastructure to deliver it ourselves at world scale.

Legion is building autonomous medical care (the AI doctor), starting with psychiatry. Our AI-native care-delivery platform currently automates 95% of the administrative work required for us to deliver direct patient care. We also recently became the first company ever to receive regulatory authorization to let AI prescribe psychiatric medications https://nypost.com/2026/03/27/business/artificial-intelligence-can-now-prescribe-mental-health-drugs/, allowing us to not only collapse health care’s admin costs but also its clinical labor costs—shifting this industry’s economics from humans to tokens.

Our technical moat is hard to copy—we combine rich data, production AI, doctors in the loop, and end-to-end care operations to deliver measurably better care to a clinically complex patient population. This has helped us produce tens of thousands of total visits in just 2 years, all while holding ops costs flat and achieving industry-leading patient NPS and retention. While the last generation of healthcare startups made the existing system incrementally more efficient, Legion is rebuilding full-stack care delivery from first principles. Our vision? A 10X better patient experience that’s higher quality, less expensive, and more scalable than ever before. And a 10X better clinician experience that frees our providers to focus on what matters most: caring for patients.

Legion Health is backed by Y Combinator, leading venture capital firms, and founders from Function Health, Modern Health, Everly Health, Trusted Health, Clipboard Health, PatientPing, Sesame Care, Faire, EasyPost, and fuboTV.

Join us as we build the future of health care: faster, higher-quality, and more affordable, powered by doctors and AI working together.

🚀 THE ROLE

Hey, I'm Daniel G Wilson https://www.linkedin.com/in/danielgwilson/, co-founder and CTO at Legion. I studied applied math and CS at Princeton, led the Office Scripts and Power Automate integration at Microsoft, and did deep learning and RL research before that. GitHub: https://github.com/danielgwilson

I'm hiring a principal-level engineer to own the hardest systems in our care platform, whole. Not tickets, not a lane inside someone else's architecture: entire problem spaces, from "this is a mess" to "this is done and here's the doc."

Here's the honest shape of the job. We run a regulated clinical product (we e-prescribe controlled substances) on an event-driven TypeScript platform, and we ship at unusual velocity with heavy agent leverage. The engineers who have thrived here share one behavior: I hand them a gnarly domain, they disappear into it, and they come back with it working, documented, and theirs. I don’t need to check their work or meddle, because checking isn’t unnecessary. Th
[…]
er engineers; this is not that. We need someone who’s seen some shit.

This role is not for you if you want to manage instead of build, you need well-scoped tickets to be productive, or big-company pace feels normal to you.

💻 OUR TECH STACK

• TypeScript, Node.js, Postgres, Next.js on Vercel, AWS, production LLM agent orchestration and bespoke harnesses, tools, CLIs, skills, evals and observability, EHR and e-prescribing integrations, PHI-grade security and audit trails.

📍 ROLE LOGISTICS, COMPENSATION, AND BENEFITS

• Job type: Full-time
• Role type: Engineering
• US Visa Sponsorship: Yes
• Salary: $250,000 to $400,000 depending on experience, plus meaningful early-stage equity in a category defining company.
• Health Insurance: Medical, dental, and vision benefits
• Additional Perks: In-person retreats, meal stipends, etc.
• Time Off: Flexible, unlimited vacation policy
• Work hours: flexible but demanding—because we are (literally) saving lives.
• Work Setup: In-person @ San Francisco HQ; partial remote considered for exceptional candidates (our track record includes both).
• Impact: Work on something that truly matters to millions of patients and families.
• Autonomy and Learning: Ownership over your projects with the freedom to set priorities, shape processes, and drive outcomes end-to-end.
• Growth Opportunities: As we scale, we envision our top performers stepping into expanded roles and joining our executive leadership team.

🤝 EQUAL EMPLOYMENT OPPORTUNITY

Legion Health is proud to be an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees, contractors, and applicants without regard to race, color, religion, sex, sexual orientation, gender identity or expression, national origin, age, disability, veteran status, genetic information, or any other protected characteristic under applicable law. We encourage applicants from all backgrounds to apply.