We seek two (2) systems software engineers, with a MSc degree in Computer Science or Computer Engineering. The candidates will contribute to the R&D activities of FORTH, in the context of the EuroHPC-funded project SPACE, in either a full-time (preferred) or part-time capacity. The SPACE Centre-of-Excellence project aims to foster the reuse and sharing of algorithms and software components in the Astrophysics and Cosmology (A&C) application domain, where High Performance Computing (HPC)-based numerical simulations are outstanding instruments for scientific discovery. SPACE aims to extensively re-engineer the target codes to engage with new computational solutions suitable for exascale and post-exascale computing systems, and to adopt innovative programming paradigms, software solutions, and libraries. The SPACE consortium will pursue this goal through co-design activities that bring together scientists, code developers, HPC experts, HW manufacturers and SW developers, advancing lighthouse exascale A&C applications, codes, services and know-how promoting the use of upcoming exascale and post-exascale computing capabilities. In addition, SPACE will address the high-performance data analysis of the data torrent produced by exascale A&C simulation applications, also with machine-learning and visualization tools. The deployment of applications running on different platforms will be facilitated by federating capabilities focusing on code repositories and data sharing, and integrating European astrophysical communities around exascale computing by adopting software and data standards and interoperability protocols.