Comment by pmontra

Yes, that must be the case because if my customers and I would care about compile time guarantees we would not be working with Ruby.

In that years long Phoenix project one of the developers on the team added dialyzer type annotations to the functions in the files he worked on. Everybody else did not bother. The project ended up with no type checking. The service run and the company did well.

Overall using Phoenix was a good experience. I never used Elixir in any other project and never for my own programs. I use several other languages for my own little scripts, mainly bash, Ruby, Python and Lua. I think that I really like dynamic typing.