Population ageing represents a growing challenge for rural and cross-border regions, where territorial dispersion and limited access to health and social services increase the risk of late detection of functional decline. The SER65 + project addresses this issue by developing an integrated digital ecosystem designed to support multidimensional assessment, continuous monitoring, and coordinated intervention for older adults. This paper presents the architecture and design principles of the SER65 + digital ecosystem, which includes a mobile application for community-based assessments and a web platform that centralizes information, facilitates communication among professionals, and enables data-driven decision-making. Building upon international guidelines for healthy ageing, the system incorporates validated assessment tools and role-based workflows. The article also reviews the scientific and technological background underpinning the platform and situates its development within broader European efforts to promote integrated digital care. The results highlight the potential of SER65 + to enhance early detection, professional coordination, and continuity of care in low-density regions.