Design, Development, Integration and Technical Validation of a Large-Scale Digital Health Platform for Remote Monitoring and Management of Patients with Advanced Heart Failure

Digital health solutions increasingly rely on interoperable software platforms that integrate heterogeneous data sources, support remote patient monitoring and deliver clinical decision support while complying with strict security, privacy and regulatory requirements. Numerous studies report the clinical outcomes or analytical capabilities of such systems. However, the engineering processes leading to their development are rarely described in a systematic manner. This paper presents the design, development, integration and technical validation of the RETENTION digital health platform for the remote monitoring and management of advanced heart failure patients. The platform was developed as a modular software ecosystem integrating mobile and web applications, medical devices, clinical and real-world data repositories, and artificial intelligence services through an HL7 FHIR-centred architecture. The complete engineering lifecycle, from requirements and architecture to software development, integration and validation, is described in this paper. Emphasis is placed on the adoption of interoperability standards, Security and Privacy by Design principles, data management mechanisms and deployment strategies that enable the integration of heterogeneous technologies into a unified platform. By documenting the complete development pathway, this work aims to serve as a guide for the design and implementation of large-scale digital health platforms that support remote patient monitoring and chronic disease management.