Comment by emidln

Code completion, refactoring aids, linting, and whole program analysis also exist in dynamic languages. Take a look at emacs with anaconda-mode for python or cider for clojure. IntelliJ in the forms of Cursive and PyCharm (or the Python IDEA plugin) also support all of these. Even vim can do this stuff (python-mode, fireplace.vim). I don't Ruby very often, but I suspect these tools exist here too.