In the world of AI mental health, vibes can be dangerous, with real consequences. Building SonderMind's Mental Health AI Coach required a new playbook for eval-driven development that balances effectiveness and safety. The team explains the clinical feedback loop that turns human therapist insights into machine-readable evaluations across thousands of conversations; the Ethics Engine of modular guardrails that can evolve with clinical guidelines; the move from single-prompt agents to a closed-loop Supervisor/Executor/Evaluator architecture; and the human oversight used to improve safety and quality. Speakers: Akele Reed — Principal AI Engineer, SonderMind Akele leads the team behind SonderMind's conversational AI mental health feature and helped architect its guardrails and evaluations framework. LinkedIn: https://www.linkedin.com/in/akele-reed Dave Revere — Staff AI Engineer, SonderMind Dave builds evaluation, guardrail, clinical-feedback, and regression-testing infrastructure for high-stakes mental health AI. X/Twitter: https://x.com/daverevere LinkedIn: https://www.linkedin.com/in/daverevere Doug Keller — Senior Staff AI Engineer, SonderMind Doug is the lead architect of SonderMind's agent platform and a core builder of its mental health coach. LinkedIn: https://www.linkedin.com/in/doug-keller/