I work for the "civil service" as we call it.
Theres no specific qualification, it depends as with all jobs on what you want to specialise in.
I'm a translator, because I'm good with languages, having being bilingual since being a very young child (english and ukrainian) + I can speak french and russian fluently.
Totally depends on what you want to do within the service, its an organisation like any other, and a myriad of different positions.