It's better to know a couple of languages - one mainstream and one non-mainstream. The JS developer's rates will gradually go down over the time due to oversatu

It's better to know a couple of languages - one mainstream and one non-mainstream. The JS developer's rates will gradually go down over the time due to oversaturation. Additionally I struggle to see the future where complete back-end including message queues, workflow engines, database API etc. are all in JavaScript. You don't want a language that dynamic for those stuff. Additionally JS as language is lacking innovation, it will be taking years for standards committee to release new versions. This is one of the reasons LLVM and asm.js are better ideas.