You said "Grande Ecole" ?

Strong “esprit de corps” and alumni network.

Phelma is what the French system calls a Grande Ecole.

After two years of preparatory classes and a strong national competition, students might enter the school and the duration of the training at Phelma is 3 years (equivalent to the third Bachelor year and the two master years).
The global approach is based on fundamentals, with a strong emphasis on mathematics and physics, and a high level of abstraction but is also based on practical work. A highly selective admission process: students are admitted through a nationwide examination or by virtue of excellent academic records.
An unwritten hierarchy: the Grandes Ecoles have always been very competitive among themselves. The resulting hierarchy is fairly stable because of the competitive admission system, where the most prestigious institutions attract the best students.

As engineering studies is concerned, the trainings offered by the French Grandes Ecoles are the best of the country in that field.

Strong “esprit de corps” and alumni network.

Doctoral studies are also offered by some Grandes Écoles since engineering degree gives the opportunity to undertake a PhD.
A small size: a ‘Grande École’ is usually of the size of a university department, with at most of 300 to 500 graduates per year.