Principal AI Engineer

Principal AI Engineer — CoTherapy.ai

Remote · North America

We're building a next-generation AI system in the mental health space that bridges the gap between clinical care and scalable digital support. Founded by a practicing psychiatrist with 20+ years of clinical experience and multiple successful exits in healthcare technology, we operate at the intersection of AI safety, personalization, and human-centered design.

We need someone who has built AI systems on clinical data — not general chatbots, not content generation tools — to own the intelligence layer that makes this system clinically safe.

Role Overview

You'll own the intelligence layer that makes this system clinically safe: the LLM orchestration pipeline, safety systems, and memory and retrieval architecture. You work directly with our CTO and CEO/clinical founder. This is a full-time, senior IC role with real technical authority from day one.

What You'll Own

• LLM orchestration: prompt assembly, context management, and multi-model routing
• Safety and compliance layer for clinical AI interactions
• Memory and retrieval architecture (vector search, RAG pipelines)
• Evaluation frameworks and observability infrastructure to ensure reliable production performance

Must-Have Experience

• Built and shipped LLM/NLP systems on clinical or health data in production — not just prototypes or academic environments
• Designed and owned a RAG pipeline end-to-end in production — not just integrated a library
• Built content safety systems for LLM outputs beyond keyword filtering; understands failure modes in high-stakes or sensitive contexts
• Instrumented a production LLM system with evaluation and observability infrastructure — can reason about model performance and degradation
• Hands-on production experience with at least one LLM orchestration framework (e.g. LangChain, LangGraph), a vector database, and cloud LLM infrastructure

Strong Plus

• Experience building AI systems handling PHI under HIPAA, PIPEDA, or equivalent healthcare privacy frameworks
• Experience designing human-in-the-loop systems for clinical workflows
• Published research or applied work in healthcare AI
• Mental health domain experience

Why Join

• Build the clinical AI system, not a wrapper — this is the product, not a feature
• Work directly with a psychiatrist who understands both the clinical nuance and the engineering constraints
• Competitive salary and meaningful equity, commensurate with experience
• A chance to define how safe, human-aligned AI shows up in mental health