> I really don't get how JS on the client and the server is any real advantage from my own experience, using single language has huge influence on overall code

> I really don't get how JS on the client and the server is any real advantage from my own experience, using single language has huge influence on overall code quality. Makes you understand it much better, comparing to situation you must switch between multiple languages. As you gain more experience in it, the less obvious bugs you'll make (just by knowing what's good and what's wrong). The worst js code I see, is coming from programmers for whose javascript is their secondary (or third) language. They simply don't understand the basics of it. For example they use timeouts to make asynchronous code synchronous, etc... Then bitching on internet how bad language it is.