European permanent officials,  are classified into three groups: Administrators (AD), Assistants (AST) and Secretaries/Clerks (ASC-SC). 
Assistants (AST) are required to have either a high school or vocational school diploma, with or without professional experience. 
However, for AST3 positions, which involve areas like financial management, project management, communication, or related subjects, a higher level qualification or professional experience is necessary. 

See also Permanent officials related FAQs.