In my experience not really because you can type hint structs, which combined with pattern matching, guards and typespecs will cover most cases. ex: def foo(%B

In my experience not really because you can type hint structs, which combined with pattern matching, guards and typespecs will cover most cases. ex: def foo(%Bar{} = bar, how_many) when is_number(how_many) Also avoiding/limiting variable rebinding should mitigate problems as the language is immutable otherwise. So IMHO it affects the developer productivity more than create type bugs, because you have to write all that and intellisense kind of sucks (at least in Jetbrains' IDE with the unofficial Elixir plugin).