The Galactica simulation database is a platform designed to assist computational astrophysicists with their open science approach based on FAIR (Findable, Accessible, Interoperable, Reusable) principles. It offers the means to publish their numerical simulation projects, whatever their field of application or research theme and provides access to reduced datasets and object catalogs online. The application implements the Simulation Datamodel IVOA standard. To provide the scientific community indirect access to raw simulation data, Galactica can generate, on an "on-demand" basis, custom high-level data products to meet specific user requirements. These data products, accessible through online WebServices, are produced remotely from the raw simulation datasets. To that end, the Galactica central web application communicates with a high-scalability ecosystem of data-processing servers called Terminus by means of an industry-proven asynchronous task management system. Each Terminus node, hosted in a research institute, a regional or national supercomputing facility, contributes to the ecosystem by providing both the storage and the computational resources required to store the massive simulation datasets and post-process them to create the data products requested on Galactica, hence guaranteeing fine-grained sovereignty over data and resources. This distributed architecture is very versatile, it can be interfaced with any kind of data-processing software, written in any language, handling raw data produced by every type of simulation code used in the field of computational astrophysics. Its generality and versatility, together with its excellent scalability makes it a powerful tool for the scientific community to disseminate numerical models in astrophysics in the exascale era.