Together with partners from the Helmholtz-Zentrum Hereon, the Technical University of Munich (Prof. W. A. Wall), Germany,  the Bundeswehr University Munich (Prof. A. Popp), Germany,  and Uppsala University (Prof. M. Kronbichler), Sweden, we are developing research software for multiphysics simulations of complex systems relying on advanced C++ libraries for high performance computing (HPC) such as Trilinos or deal.ii. We use this software for the development of digital twins for various applications including aerospace engineering, renewable energies, biomedical engineering and materials science.