At the Groups and Clsuters of Galaxies (GCG) group at the University of Helsinki, we are studying the physics of the largest gravitaitonally-bound strucutres in the Universe with state-of-the-art observational data from international projects. Our research utilizes multi-wavelength data from prime projects (e.g., eROSITA, XMM-Newton, DESI, Euclid) to identify groups and clusters of galaxies, and probe the properties of their intragroup/cluster medium. We are members in several international projects such as the current CHANCES survey of the 4MOST, J-PAS, X-GAP, and the future X-IFU/Athena, and MOSAIC/ELT.