Traineeships beginning in October applications open in January.
Traineeships beginning in March aplications open July–August.
Every single application is assessed on the basis of academic profile, language skills and additional qualities. A ranking is then established and the 2,800 candidates with the highest scores are shortlisted.
The applications which do not comply with the formal requirements are rejected.
The Commission units select candidates according to their specific needs and criteria (languages, studies, experience, etc.). Some 650 trainees are recruited for each session.