In the EU hierarchy, the first managerial position is that of a Head of Unit which is considered a rather senior function given that at least 9 and in some cases 12 years of work experience is required to be appointed as a Head of Unit.
Only Administrators can assume such positions and they must have AD9 grade or higher to be eligible. EPSO recruits Head of Unit in a similar fashion as other Administrators with the exception of having additional requirements for leadership and managerial skills.
See also:
Function Groups | Administrators (AD) | Eligibility Requirements | Assessment Centre