Today’s statically-typed functional programming languages give developers great confidence over correctness and an excellent tool during refactoring. With tools like core.typed (Clojure) and Dialyzer (Erlang), dynamically-typed language users are able to take advantage of many of these benefits as well. In this talk, we’ll explore the success typing space. Further, we’ll see some real-world examples where Basho has used Dialyzer to create better assuredness and documentation in their database: Riak.