[hwntw]

Erlang might be slightly more obscure, but there are plenty of big household names using the language - Klarna, Bet365, and William Hill are all household names. And that's excluding the obvious cases of Ericsson or WhatsApp.

[scarface74]

Except for WhatsApp, from what I can find on Levels, all of the companies you named pay on the low end of even enterprise dev salaries.