In Trust we Build: Engaging Disciplinary Communities in Service Development - Early Experiences from Base4NFDI

Research data management (RDM) is a key enabler of Open Science, providing the foundation for transparent, collaborative, and reusable research practices. In Germany, the National Research Data Infrastructure (NFDI) coordinates efforts across disciplines to develop sustainable, interoperable data. Developing sustainable, discipline-sensitive services in this area requires more than technical excellence: it calls for a framework that connects technical rigour and quality with active user engagement and domain expertise. The Base4NFDI initiative addresses this challenge through a bottom-up approach, driven by infrastructure experts who are closely connected to disciplinary research communities. This ensures that emerging services are both technically robust and directly aligned with diverse research needs.Service development follows a three-phase model. In the Initialisation phase, a oneyear program of requirement analysis, persona-based modeling, and prototyping is carried out, complemented by early engagement with stakeholders to identify reusable patterns and integration opportunities. In the Integration phase, candidate services are embedded into real disciplinary workflows through incubator projects with NFDI consortia, which enable co-development, integration within disciplinary communities, and policy alignment. Training and user studies further support adoption, while early success stories demonstrate impact and encourage take-up. In the ramp-up phase, services prepare for long-term operation by establishing governance structures and sustainable models, and where applicable, aligning withthe German EOSC node to ensure interoperability and compliance at the European level.A concrete example is IAM4NFDI, which makes it possible for institutes to share their infrastructures beyond local boundaries. For researchers, this means that resourcespreviously tied to a single institution become accessible to a wider community, enabling collaboration and opening new opportunities for data-intensive work. For institutes and service providers, it creates a sustainable way to make their infrastructures available to broader audiences without duplicating effort. In this way, IAM4NFDI supports both sides of the Open Science ecosystem: researchers gain easier access, and providers ensure that their services are used more widely and effectively across disciplines.Building on this principle of shared, accessible infrastructure, Jupyter4NFDI provides a central JupyterHub that supports teaching, reproducible analysis, and collaborative research. Like IAM4NFDI, it empowers researchers with an easy entry point to Open Science workflows while enabling institutes to contribute their backend resources in a sustainable way without managing access individually. Together, these services illustrate how Base4NFDI creates community-driven, interoperable tools that benefit both researchers and service providers.By combining phased development with close collaboration between infrastructure experts of the discipline-specific NFDI consortia, Base4NFDI delivers services that areopen, interoperable, and responsive to real research needs. This bottom-up approach builds trust by re-using and opening institutional infrastructures under transparentgovernance, allowing researchers to help shape solutions they can rely on. In doing so, it ensures sustainability while strengthening the foundations of Open Science both on a national level and beyond.