NSs and BHs are among the most exotic objects in the universe and the ultimate endpoints of massive star evolution. A better knowledge of their origin, evolution, and feedback onto the interstellar medium is essential to understand the evolution of the Galaxy as a whole. eRASS will for the first time unveil the X-ray faint, most populated end of the Galactic population of these exotic objects. The main aim of the proposed research is to fully characterize the X-ray galactic populations of accreting NSs and BHs by combining the eRASS data with archival data and follow-up observations. It will enable us to discover the long-sought missing links in the evolution paths of BH and NS systems.