L'essentiel à retenir :

"If you want a solid start to a career, don't learn a framework and a framework's abstraction; learn the fundamentals.
Don't learn Express's routing system; learn how HTTP works.
Don't get familiar with ActiveRecord hacks to make your queries faster, learn to write SQL.
Don't learn how to build React with Redux with Bootstrap with JQuery, learn HTML, CSS and JavaScript.
For 99% of what you need to do, they will be more than enough.
This knowledge will never get stale.
Unlike frameworks."

via Le Hollandais Volant