The European Health Data Space (EHDS), entering into force in 2025, demands a new generation of professionals capable of navigating interoperable health ecosystems. This paper investigates how healthcare professionals enrolled in the ManagiDiTH master’s programme perceive and critically assess interoperability implementation across sectors and countries. Drawing on 72 structured case studies from students from multiple countrie, we apply qualitative thematic analysis along a before/after/challenges axis. Results reveal systemic fragmentation as the pre-interoperability baseline, measurable transformation following implementation, and persistent challenges including legacy systems, digital skills deficits, and governance misalignment. Three emergent professional profiles are identified: the Digital Health Leader, the Interoperability Specialist, and the Digital Health Policy Analyst. We argue that structured educational exposure to interoperability transitions develops foundational competencies for digital health leadership in the EHDS era.