Pop's group builds superconducting quantum circuits from high-kinetic-inductance materials, above all granular aluminium, and uses them as detectors. The distinctive capability is single-microwave-photon detection and QND photon counting with superinductor-based devices -- an extremely low dark-count, quantum-limited receiver in the GHz band -- plus fluxonium-type qubits, quantum-limited and travelling-wave parametric amplification, and studies of quasiparticle and noise mechanisms that set coherence limits. The direct sensing payoff is dark-matter search: a photon counter that beats the standard quantum limit lets a haloscope integrate far faster than an amplifier-based readout. Relative to the established NV-ensemble quantum-sensing playbook (DEER, nanoscale NMR, T1 relaxometry at pT/sqrt(Hz) ensemble sensitivity), this is the microwave/superconducting counterpart to an NV ensemble -- same objective (detect an absurdly weak field), different physical platform and roughly opposite temperature regime. A recent addition to Stuttgart's 1st Institute of Physics, so the lab is being built out now, which usually means unusual latitude for a postdoc.