Public-Private Learning Communities (PPLCs) provide a collaborative environment where public and private organisations join forces to work, learn, and innovate together. Digital platforms can facilitate the primary processes in these networks. However, there are no design paradigms or reference architectures to support the development of a collaborative platform tailored to PPLCs. This doctoral consortium paper aims to introduce a novel design approach comprising two artefacts: a reference ontology that contains essential domain knowledge for a collaborative platform tailored to PPLCs and a reference architecture to guide platform development. A design science research approach is adopted, combining participatory research methods to explore the problem context of PPLCs and technical action research to iteratively design and evaluate prototypes of the artefacts. This doctoral research will generate new design knowledge regarding collaborative platforms for PPLCs and evaluate the reference ontology and -architecture using case study research in PPLCs.