Oberlack leads Mainz's contribution to the XENON/XENONnT dual-phase liquid-xenon dark-matter programme at Gran Sasso, covering detector instrumentation, ultra-low-background material screening, light and charge readout, and the associated rare-event analysis; the same detectors also probe neutrinoless double beta decay and coherent neutrino scattering. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), this is an astro-particle pivot: the shared discipline is single-quantum detection at absurd background rejection, and the group is a natural landing spot for a quantum-sensing postdoc interested in low-background readout electronics or in the growing overlap between quantum sensors and dark-matter searches.