Interoperability of Web Archives and Digital Libraries: A Delphi Study The interoperability of web archives and digital libraries is crucial to avoid silos of preserved data and content. While various researches focus on specfic facets of the challenge to interoperate, there is a lack of empirical work about the overall situation of actual challenges. We conduct a Delphi study to survey and reveal the insights of experts in the field. Results of our study are presented in this paper to enhance further research and development efforts for interoperability. 19-28 19-28 Biblioteca Nacional de Portugal