Hydrodynamical simulations of galaxy formation have become a central tool in extragalactic astronomy and cosmology. They underpin the interpretation of observations of galaxy evolution and provide predictions for cosmological surveys. I will discuss why their realism has improved dramatically in recent years, and where the main challenges remain. I will then introduce COLIBRE, a new suite of simulations designed to overcome several key limitations of earlier generations. COLIBRE explicitly models the multiphase interstellar medium, including the formation and evolution of dust grains. It suppresses the spurious transfer of energy from dark matter to baryons through dark matter super-sampling, and its largest volumes contain an order of magnitude more resolution elements than previous flagship runs. I will present a selection of first results on galaxy evolution across cosmic time. The simulations agree remarkably well with a wide range of observations over the full accessible redshift range, but they also reveal intriguing discrepancies that may point to gaps in our understanding of galaxy formation.
