Not Impressed
Honestly, I really hate when these tech companies are always claiming the cutting edge languages out there are the next big thing and we're adopting them ALL!! I mean, C++ has its place. For back end stuff, I still haven't seen anything that is really that much better than Java and it has been around forever much like C++, tried and true. Python has definitely gained some footing but Rust and Hack?? Gotta say, I'm not much of a fan of PHP either especially for enterprise type development.
The reason this is such a pain in the ass is that IT managers look to these companies and go... I know we've got 2 million lines of code in Jave, C++, .Net but Facebook says RUST or Hack is the best. I want you all to convert the system over to RACK!! Do it yesterday, no bitching.
There are so many languages out there... It is nearly impossible for developers to keep up on them all unless they are like Facebook and Google employees who never sleep. Just kick out code 24/7 or Zucherberg fires them. I dunno. I'm not impressed.