Founding Engineer AI-Native

Founding Engineer (AI-Native)

San Francisco, CA (Onsite)
Full-Time

About the Company

Legion Health is a fast-growing, YC-backed healthcare technology startup building AI-native mental health care systems. We specialize in telepsychiatry and medication management, delivering high-quality, insurance-covered care with rapid access for patients.

Founded in 2021 and headquartered in Austin, TX, we are redefining how clinicians, patients, and AI systems collaborate to deliver better mental healthcare.

About the Role

We’re hiring a Founding Engineer to build the core systems powering our autonomous care platform.

This is not just an infrastructure role—you’ll architect and own the product’s core engine, designing workflows, AI agent behavior, and backend systems that connect patients, clinicians, and intelligent agents into one cohesive system.

You’ll work directly with founders and take full ownership of critical systems, helping shape both product and technical direction.

What You’ll Do

• Architect and scale event-driven backend systems using Node.js, TypeScript, and Postgres (Supabase)
• Build and deploy LLM-powered agents with tool usage, memory, retries, and safety guardrails
• Design state machines and workflows for real-world healthcare processes
• Develop internal tools and dashboards for human AI operations
• Own data pipelines, compliance (HIPAA), and system reliability
• Collaborate with Product, Clinical, and Design teams to ship production features weekly

Tech Stack

• Backend: Node.js, TypeScript, Supabase (Postgres), AWS (ECS, Lambda, S3)
• Frontend: Next.js 15, Tailwind, Vercel
• AI: OpenAI, Anthropic, embeddings, vector DBs, agent frameworks
• Other: Real-time schedulers, audit logs, PHI-compliant systems

Basic Qualifications

• Proven experience shipping production systems using TypeScript, Next.js, and Postgres
• Strong backend/system design skills (data modeling, workflows, APIs)
• Experience building stateful systems with clear invariants and transitions
• Ability to build both frontend (UI/tools) and backend systems
• Comfortable in fast-paced, high-ownership startup environments
• Willing to work onsite in San Francisco

Preferred Qualifications

• Experience with LLMs, AI agents, or RAG systems
• Background in healthcare, fintech, or regulated industries
• Early-stage startup or founding team experience
• Experience building internal tools or ops dashboards

What We’re Looking For

• Engineers who think in systems, not just endpoints
• Builders who can translate ambiguity into working products
• High ownership mindset with strong execution speed
• Passion for AI-native product development
• Strong communication and collaboration skills

Nice-to-Have Signals

• Built and scaled products with 10K–100K users
• Experience debugging real-world system performance
• GitHub projects with strong traction (stars, contributions)
• Experience shipping production LLM features

Why Join Us

• Founding-level ownership with meaningful equity (0.2%–0.8%)
• Work on mission-critical healthcare impacting millions
• High autonomy and rapid growth opportunities
• Direct collaboration with founders and leadership
• Fast hiring process (7–10 days)

Benefits

• Health, Dental, Vision Insurance
• 401(k)
• Unlimited PTO
• Meal stipends & team retreats
• Flexible but high-impact work environment