As a part on an ongoing formative evaluation, we examine the role of participation and engagement of one crucial stakeholder group (service providers) for the development of a digital platform for health promotion and preventive services in settings (DIFA) by the German Association of Private Health Insurers. DIFA is being developed to become a major digital infrastructure for providing health promotion and prevention services for settings (communities, schools, kindergartens etc.) in Germany. It will enable service providers to manage their collaboration with different setting actors online, provide consulting and qualification services as well as to foster and extend their networks online.