The goal of the course is to provide the students with the theoretical background and the hands-on experience of two numerical approaches to treat the quantum-many body problem in condensed matter: (a) Density Functional Theory, i.e. the current “workhorse” for the calculation of electronic structure, structural energies and interatomic forces in real molecules and solids and (b) and Quantum (variational, diffusion, path-integral) Monte Carlo.