Panel answer: no. Node.js faces heavy competition on the backend; Rails is better for quick prototyping and Elixir is better for heavy lifting. Ruby/Elixir/etc. remain viable because customers can still be convinced to pick them, and the job market in 2018 is optimistic. Developers have transpilers (Opal, PureScript, etc.) so they don't need to write JavaScript directly. Unlikely any one language will break the others' markets rapidly.