Health Tech comes with unique challenges, from data privacy laws, mission-critical uptime, to clinical validation. Further complicated by an industry resistant to change, weighed down by complex legacy enterprise systems and data silos. Learn valuable insights from our journey as an addiction care startup, transitioning from a monolith MVP engineered in isolation, to GraphQL Federation built alongside clinicians. By involving domain experts in design thinking exercises, we not only constructed subgraphs with build-in clinical validation, data governance, and security, but also transformed our clinical end-users into champions for change.