On: Facebook, Instagram go down around the world in an...

[duado]

So that engineers can be moved between product groups while carrying relevant knowledge and experience with them.

[yellowapple → duado]

I'm pretty sure a bunch of Erlang programmers being shoehorned into a PHP codebase is the literal definition of Hell for all parties involved.

[duado → yellowapple]

Facebook is not a “PHP codebase.” I’d guess that fewer than 0.01% of CPU cycles at Facebook are used by PHP.

[nothal → duado]

Isn’t a significant amount of the codebase in Hack, a PHP derivative?

[Lt_Riza_Hawkeye → nothal]

C++ is the most popular language at Facebook, I know that one for sure. They used to run PHP on HipHop VM which was written in C++, but now they transpile PHP to C++.

[yellowapple → Lt_Riza_Hawkeye]

The transpiler is HipHop. They discontinued that in favor of HHVM, which does JIT compilation instead. More info: https://hhvm.com/

EDIT: apparently, though, HHVM stopped supporting PHP itself last month; now it only supports Hack. I'm not familiar enough with Hack to know how much it actually deviates from / improves upon PHP.

[macintux → duado]

If that’s the goal, why not start incorporating more Erlang into the rest of Facebook instead? It proved its mettle at WhatsApp.

[duado → macintux]

Facebook has to hire thousands of engineers per year. They may incorporate more Erlang into Facebook, but they have to have a core tech stack that can easily onboard engineers from a variety of backgrounds. I don't have the foggiest idea of whether Erlang can be part of that or not, but people talk about it as if it's a special-purpose tool.

[kevsim → macintux]

Facebook was actually using Erlang way before WhatsApp

https://www.quora.com/Why-was-Erlang-chosen-for-use-in-Faceb...