Community engagement and uptake: lessons learnt in EPOS, the Research Infrastructure for Solid Earth Sciences.

The path from the conception of a disruptive and innovative Research Data Infrastructure (RDI) to a successful operational RDI, is influenced almost entirely by the ability to engage at equal levels, researchers, IT experts, practitioners and data providers in its usage and adoption. This is particularly true for distributed RDI.In this work, we present the lessons learnt in EPOS (European Plate Observing System), the unique, distributed pan-European Research Infrastructure in the solid Earth domain. In EPOS a series of challenges were faced, in terms of consensus-driven choices along the technical, governance, sustainability, and scientific dimensions.EPOS is built for promoting collaboration, and harmonization of heterogeneous datasets, practices, and methods from ten different solid Earth communities. The final goal is to foster innovation and facilitate novel scientific discoveries. EPOS is a large research infrastructure including more than 60 data and service providers from 25 European Countries, providing 250 data services, delivering more than 30 different data formats, and covering more than 800 TB of data in total, described by more than 20 different metadata standards. It was conceived back in 2002, included in the ESFRI (European Strategic Forum on Research Infrastructures) Roadmap in 2008, then implemented through three European Projects (EPOS-PP Preparatory Phase (2010-2014), EPOS-IP Implementation Phase (2015-2019), EPOS-SP Sustainability Phase (2020-2023). EPOS was granted the status of ERIC (European Research Infrastructure Consortium) in 2018 and is in its Operational Phase since January 2023.The first lesson learned in this journey is related to the need for procedures and boards for community building and consensus establishment; this was achieved through clear governance where all key stakeholders interact and are informed through appropriate boards and committees. The second one is technical: to integrate such heterogenous datasets into a single platform (the EPOS Data Portal) a flexible architecture based on the microservices approach was adopted. The third lesson is related to the description of the datasets and services provided by the various thematic communities in EPOS, achieved through a rich metadata model that maps enough information to drive the integration occurring at the central system underpinning the EPOS Data portal. The fourth lesson is related to the legal and governance aspects: to keep communities committed, legal agreements for governance and coordination and for the thematic data provision were established; this ensures community engagement and the adoption of common criteria and principles.Finally, the fifth lesson is related to the co-development approach. For managing decisions and consensus on key technical and scientific aspects within a community of more than 80 individuals with different roles, responsibilities and expertise, a clear process was set up. It is inspired to the shape-up methodology but reviewed for the research context, and it proved to be effective in the EPOS RI where international collaboration is needed to manage integrated data provision.Many challenges remain open, for instance how to recognize and to encourage the careers within RDI. These indeed require specific skills, and the assumption of responsibilities within the RDI should be recognized by setting up dedicated career paths.