NSF–DOE Vera C. Rubin Observatory has officially begun full operations for the Legacy Survey of Space and Time (LSST), one of the world’s largest astronomical imaging surveys. Behind the scenes, Japanese researchers and engineers are drawing on technologies and expertise cultivated through the development and operation of the Subaru Telescope to support the project’s software, systems and operations. More than 80 researchers from Japan are already participating in LSST science through access to its data. Looking ahead, the combination of Rubin’s wide-area survey and the Subaru Telescope’s detailed follow-up observations will help advance our understanding of fundamental mysteries of the universe.