Implementing a Cost-Efficient and Interoperable Health Data Infrastructure: A Multi-Region Finnish Case Study

This paper examines a large-scale, collaborative data infrastructure project implemented across three Finnish wellbeing services counties in response to national health reform mandates. Using a qualitative case study approach and the European Interoperability Framework (EIF), this paper analyzes how organizational, political, semantic, and technical interoperability were jointly managed to develop standardized yet distributed data lake solutions. While legislative obligations drove the collaboration, success required close operational coordination, agile methods, and shared technical frameworks. By deploying parallel yet aligned environments, the counties achieved standardized reporting, reduced duplication, and improved cost-efficiency. The case highlights that sustainable digital health reform demands a holistic approach integrating top-down mandates with localized coordination and technical agility, ensuring all EIF dimensions are consistently addressed. Future evaluations should assess the long-term cost-effectiveness, scalability, and governance sustainability of this standardized, distributed model.