The FOSSR cloud infrastructure is built upon a federated network of high-performance data centers, designed to support large-scale social science research in a scalable, secure, and resilient manner. Currently comprising four operational nodes located at CNR Institutes in Naples, Palermo, Turin, and Catania—with a fifth node being activated in Pisa—the network provides access to 247 HPC servers, 52 GPU units, and over 8.5 petabytes of storage capacity. This hierarchical configuration, distinguishing between first- and second-level nodes, allows for optimized load distribution, operational continuity, and service replication in the event of failures or demand spikes. The software stack is based on a dual architecture: the infrastructure layer, built on OpenStack, enables virtualization, dynamic resource allocation, and advanced cloud service management, while the application layer, leveraging Kubernetes, Rancher, and Docker, supports orchestration and scalable deployment of containerized services and also provides the FOSSR web portal and a marketplace. This two-tier system offers users a broad range of environments for executing virtual machines or containers, tailored to the specific needs of computational social research. Looking ahead, the infrastructure is designed to evolve into a fully FAIR-aligned federated platform, integrating AI-ready resources, supporting virtual research environments, and enabling interoperability with hybrid and multi-cloud architectures. In this way, the FOSSR HPC cloud positions itself as a strategic enabler for data-driven social science, facilitating new models of analysis, sharing, and co-production of knowledge.