We present recent work on engineering ferromagnetic-superconducting Josephson junctions using two ion-based approaches in high-temperature cuprate systems.First, we demonstrate a method for locally implanting cobalt into YBCO films using a focused liquid metal alloy ion source. The resulting devices exhibit both metallic conductivity and superconductivity—despite operating well below Mott’s minimum metallic conductivity—indicating unconventional transport likely influenced by magnetic scattering or spin-related interactions.Second, I will present results from Josephson junctions fabricated from YBCO/LSMO heterostructures, where nanoscale barriers are defined via helium ion irradiation. The observed I–V characteristics reveal signatures consistent with magnetic asymmetry and a potential superconducting diode effect arising from the magnetic interface.These studies highlight how localized magnetic modification and magnetic proximity can be used to control superconducting transport and open new possibilities in high-Tc superconducting spintronics.