Python, Javascript (via Typscript), PHP, Elixir
have embraced Gradual Typing/Type Inference.You use typed variables/typed function signatures when it's convenient, they give you some compile-time contracts, easy documentation and probably even speed. Otherwise they don't exist. I don't do Ruby, but Gradual Types/Type Inference is a no-brainer for dynamic languages, practically no drawback, only benefits. (And popular statically typed languages such as C/C++, Java, Rust support Type Inference, or are going there too.)