I had colleagues that went through École Polytechnique and the Corps de Mines (usually reserved to the top 2 graduates of a given graduating class of several grandes ecoles) that then went on to work for the government. And I think it's still mandatory to work a certain number of years in the administration after going through some of the grandes écoles, not sure if that was changed (I graduated in 2012 so it was a while ago).

Of course not everyone is graduating with a technical degree, but coming from Germany where top politicians often don't even have a finished university degree and high-ranked politicians are regularly found out to have been plagiarizing their PhD work it was pretty impressive to see a working elite system. It also has some negative aspects and nepotism is a thing as well (in the sense that people who went through the system know how to game it to get their children in with high probability) but it's much better than what we have here, in my opinion.

Germany was and still is scared of anything that can be considered elitist as people always associate it with the elitism from the Third Reich.