This document provides a comprehensive overview of the activities related to building data management services and of the architectural discussions about the EUDAT Common Data Infrastructure (CDI) that were conducted during the first year of the EUDAT2020 project. The service building activities concentrated on the consolidation and integration of the existing EUDAT services and on the uptake of new community requirements initiated from the community uptake plans and data pilots or as a result from Joint Result Activities (JRA). The discussions about the architecture of the EUDAT CDI focused on the definition of the data model used, the layered architecture and the support for metadata within the CDI. In addition, a service building roadmap was defined to facilitate communication between EUDAT and the communities and project enablers about new releases of the services and supported functionalities – the roadmap is updated every half year. Furthermore, a procedure for identifying the requirements for new or proposed services was established – this will make it easier to adapt the EUDAT CDI network to any new requirements in an agile way.