About Legion Health

Legion Health (backed by Y Combinator) is building autonomous mental healthcareAI that takes real responsibility across the full care loop: before the visit during the visit and after the visit.

We run our own psychiatric practice which means we ship into realitynot theory. Were rebuilding the patient experience end-to-end:

• Outside the visit: scheduling intake benefits checks paperwork reminders care coordination billing risk detection follow-ups and patient messaging

• Inside the visit: visit support real-time note scaffolding structured history capture differential reasoning support diagnostic signal extraction treatment planning assistance medication decision support and clinician workflows that make great care feel effortless

Not doctor-in-a-box. Not a layer of prompts. Were building AI teammates that clinicians can trustagents that do the work show their reasoning handle edge cases and escalate cleanly when humans need to step in.

Our agent system already supports 2200 patients with a tiny team. The systems you build go straight into production and show up in patient outcomes clinician velocity and the quality of careimmediately.

Legion exists to make mental healthcare fast affordable and excellent at scale. This role is one of the highest-leverage ways to get there: youll help turn clinical judgment into reliable systems and turn AI from a tool into a true operatorso patients get sharper care and clinicians get their time back.

Role: Founding Engineer AI-Native Mental Health Care (In-Person in SF)

HeyIm Daniel Wilson co-founder & CTO at Legion. I studied applied math CS at Princeton then led the Office Scripts Power Automate integration at Microsoftshipping the highest retention-driving feature in the product. Before that I did deep learning RL research. Im obsessed with building AI systems that make real workflows cleaner safer and more autonomous. Github: hiring a Founding Engineer to own core product agent systems end-to-end. Youll build the layer that coordinates patients clinicians and AI agents as one coherent machinetight feedback loops high standards and real ownership.

This isnt just infra. Its building the product heart of an autonomous care system: the workflows the agent behaviors the guardrails the integrations the UX that makes it usable and the reliability that makes it trusted.

Roles evolve quickly hereincluding mine. Im looking for someone who wants to carry real weight take full ownership and grow into running major parts of the systemnot someone who needs a perfectly scoped box to operate inside.

What Youll Do

• Own our event-driven backend Architect and scale our / TypeScript / Supabase (Postgres) / AWS stack. Design schemas invariants and workflows that encode how psychiatric care actually operates. Turn messy real-world processes into clean state machines and event streams.

• Build real LLM agents as coworkers Implement tool use retries memory and safety rails. Design action schemas and evaluation loops so agents can run reliably in production. Work on orchestration context management and multi-step workflows.

• Shape human AI ops UX Build internal tools used by both humans and agents. Make it trivial to see what happened why and what should happen next in any patient journey.

• Define world-state & simulation Model the canonical state of a patients journey across time. Power alerting routing and decision-making from that live simulation.

• Own data safety & compliance Engineer HIPAA-compliant pipelines for transcripts events and EHR data. Ensure PHI access agent actions and human overrides are all auditable.

• Drive architecture & strategy Work directly with me to debate tradeoffs define new primitives and decide what we build next.

You dont need to be a pure backend engineerwe value great product engineers who can learn fast make strong simplifying decisions and grow into owning backend/agent systems.

You Might be a Fit If

• Youve owned real systems 01 or 1N not just tickets.

• You think in events state and invariants not just CRUD endpoints.

• Youre either already LLM-fluent or a strong systems/backend engineer who can get dangerous fast.

• You care about velocity and correctnessmoving quickly while keeping things understandable and robust.

• You like small high-candor teams and direct feedback.

• You want to see your work go live in production weekly not sit on a roadmap.

Nice to Have

• Experience with / TypeScript Postgres or Supabase.

• Experience with LLMs agents tool-calling or RAG.

• Experience in healthcare fintech or other regulated / high-stakes domains.

• Experience in early-stage startups or founding teams.

Our Tech Stack

• Backend: TypeScript Supabase (Postgres) AWS (ECS Lambda S3)

• Frontend: 15 (App Router) Tailwind Vercel

• AI: OpenAI Anthropic tool-calling agents embeddings vector DBs Langfuse-style observability

• Other: PHI security audit trails real-time schedulers transcript ingestion

How to Apply and Hiring Process

• Apply here: of our hiring process:

  1. Systems/portfolio deep dive (45 min) walk through 12 systems youve shipped; architecture tradeoffs failure modes.

  2. Practical work trial (1.5 hours) short realistic backend/LLM-systems exercise. No LeetCode no puzzles.

  3. Final onsite (1.5 hours) meet the team pair on a real issue and talk through how youd own a domain.

• Estimated time-to-hire: 710 days

• Start date: ASAP

Role Logistics Compensation and Benefits

• Job type: Full-time

• Role type: Engineering

• Ideal Experience Level: Doesnt matter if youre cracked

• US Visa Sponsorship: Yes

• Salary: Competitive

• Early-Stage Equity: 0.2%0.8% meaningful early ownership

• 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 were literally saving lives

• Work Setup: In-person @ San Francisco HQ

• 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 from our founding team 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.

Required Experience:

IC