I’m not 100% sure about the second factor but the first is definitely a big factor. There’s no institution which is more dense in STEM talent than ENS to my knowledge, and elites there are extremely generalist compared to equivalent elites I’ve met in other countries like the US (e.g. MIT) for instance. The core of “Classes Préparatoires” is that it pushes even the world best people to grind like hell for 2 years, including weekends, every evenings etc.
ENS is the result of: push all your elite to grind like crazy for 2 years on a range of STEM topics, and then select the top 20 to 50.
I’m not 100% sure about the second factor but the first is definitely a big factor. There’s no institution which is more dense in STEM talent than ENS to my knowledge, and elites there are extremely generalist compared to equivalent elites I’ve met in other countries like the US (e.g. MIT) for instance. The core of “Classes Préparatoires” is that it pushes even the world best people to grind like hell for 2 years, including weekends, every evenings etc.
ENS is the result of: push all your elite to grind like crazy for 2 years on a range of STEM topics, and then select the top 20 to 50.