Changala's group develops cavity-enhanced frequency-comb and microwave spectroscopy to measure molecules, radicals and molecular ions with extreme precision and sensitivity, resolving rovibrational structure relevant to fundamental physics and astrochemistry (borderline inclusion: precision molecular spectroscopy). For context, this complements the established paradigm of NV-diamond ensemble magnetometry (Hahn-echo/DEER, nanoscale NMR, T1 relaxometry) operating near pT/√Hz sensitivity.