Between pattern matching and typespecs you get a lot of the "hey you're doing something wrong" checks at compile time to avoid errors. Definitely not a complete solution; a language like OCaml or F# will be better if you're concerned about type safety.

The dynamic typing in Elixir/Erlang is a trade-off for Actor model message passing. You get a state of the art run-time for fault tolerance and concurrency, but the messaging aspect makes typing problem-prone. A co-dependency on a custom type is coupling you want to avoid when sending messages around. You don't want a long running process that knows about Type_v1 sent a message from a newer process messaging with Type_v2.

The Aeternity team is building blockchain systems with Erlang for nodes and infrastructure. However since smart-contracts necessitate so much type safety and formal verification - they're designing an ML flavor functional language just for that.