Compact objects (white dwarfs, neutron stars, or black holes) are stellar 'fossils' bearing critical information about the Galactic stellar evolutionary history. In binary systems, hidden compact objects can be revealed by monitoring the 'wobbling' effect of the visible companion star. We utilise efficient wide-field spectroscopic surveys like LAMOST (a.k.a. the GuoShouJing telescope) and high-precision photometric surveys like TESS to hunt for binary systems containing a compact object and a luminous companion star. I present our methodology and recent discoveries, introducing three interesting systems characterised by phase-resolved observations, and posting questions about explorations and exploitations of current and future time-domain surveys.