They also used to be "pretty jazzed about Elixir" and had it in their stack [1], at least while Steve Cohen was there (btw, Steve is also the author of lexical[2] - one of the newer Elixir LSPs out there)

[1] https://web.archive.org/web/20160203120655/https://engineeri... [2] https://github.com/lexical-lsp/lexical