“Athena” Research and Innovation Centre (ARC) participates in STELAR with its Information Management Systems Institute (IMSI) (https://imsi.athenarc.gr). IMSI conducts R&I activities in the areas of data management and large-scale information systems, being one of the leading institutes in the EU in Big Data and Semantic Web technologies, i.e., the foundations of the Data Economy, with particular emphasis on geospatial and spatio-temporal data. This is apparent in the quantity and quality of scientific publications in these fields, as well as from the success in obtaining competitive funding from EU and national programs, with more than 90% of IMSI budget coming from competitive funding. Moreover, IMSI has successfully led the design and implementation of several large-scale realworld information systems (e.g., hellenicdataservice.gr, geodata.gov.gr), daily offering their services to thousands of users. IMSI members participate in several international and EU standardization initiatives and domain-specific WGs (e.g., INSPIRE, OGC, OSGeo, EOSC). IMSI is promoting the open data agenda in Greece, having founded geodata.gov.gr, appointed an Excellence Center in Open Source GIS, and organizing Open Data days and hackathons. Role in the project. ARC is the project coordinator and will also lead the work in WP2 regarding data discovery and quality management. Specifically, ARC will lead the design of the architecture and the development of the data catalog, the knowledge graph, and the data profiling tools, in close collaboration with UoA, TUE and RM.