Regarding non-permanent jobs like temporary agents, a similar selection takes place.
EU open competitions are published in the C series of the Official Journal (OJ) of the European Union.
The OJ gives the specific conditions and requirements for each published competition, along with an indication of the number of posts available.
Written tests involve essay-type exams and candidates may have to write something based on analysis of information provided.
This number indicates how many successful candidates will be placed on the reserve list, however, it does not guarantee that all of them will actually get a job.