The design of new materials with specific physical, chemical, or biological properties is a central goal of much research in pharmaceutical and materials science. However, due to the combinatorial nature of chemical compound space (stoichiometry space), brute-force computational screening of all possible compounds for interesting properties is beyond any current capacity. Consequently, when it comes to properties or systems that require first principles calculations, reliable optimization algorithms must not only trade-off sufficient accuracy and computational speed, but must also aim for rapid convergence in terms of number of compounds "visited". I will briefly discuss recent progress on two fronts: Accuracy of calculated properties and efficient sampling of compound space. Specifically, density functional theory (DFT) based estimates of interatomic two- and three-body van der Waals contributions to binding energies in gas and condensed phase systems will be presented. Thereafter, I will show how inclusion of nuclear quantum effects can qualitatively alter the classical free energy landscape of proton transfer reactions using DFT based path-integral ab initio molecular dynamics calculations of DNA base pair models at room temperature. Finally, a DFT approach for constructing high-dimensional yet analytical property gradients in chemical compound space will be discussed. I will conclude the presentation with an outlook on potential future design projects that crucially depend on the availability of high-performance computing capabilities.