DescriptionNuclear fusion, which harnesses the energy of the stars, promises nearly limitless carbon-free energy. In order for fusion to become economically viable, special reactors need to be designed. The scientific and engineering multidisciplinary challenges involved in building such reactors are enormous: the plasma core needs to be kept at millions of degrees so that fusion can occur while preventing the reactor walls from melting from that heat and making sure that this heat bleeds out smoothly from the plasma. Currently under construction in Southern France, the ITER experiment is expected to show the feasibility of fusion energy. In order to optimize its operation, as well as the next-generation reactors, highly optimized plasma code simulations running on exascale-grade supercomputers are necessary. In order to tackle this task, the European Consortium for the Development of Fusion Energy (EUROfusion) has created three HPC Advanced Computing Hubs (ACH). Those hubs participate in the improvement of existing European simulation codes to enable researchers to take full advantage of the new capabilities offered by the new generations of supercomputers. This mini-symposium will introduce the fusion HPC programme and present current HPC software development carried out at the ACHs.