Deliverable D2.5 presents the first version of the High-Level Architecture of RESCALE. It receives inputs from previous deliverables: D2.1 - Use Case Specification (first Version) & D2.3 - Technology Analysis and Requirements Specification (first version), and correlates those findings to showcase an initial version of the architecture to be developed and utilized within the project. This initial process aims to identify architectural components, blocks that provide specific functionalities or services, separation of concerns, interactions, and information flow. These elements will help lay the groundwork for building the RESCALE platform and achieving the project’s goals. This deliverable will be followed by D2.6 - High Level Architecture (final version) in Month 23.