For me it is somewhat different: I always used typed languages and occasionally have to read and improve untyped code. I must admit, I feel half blind in the latter. When debugging a python web service, trying to figure out the control or data flow, I very often scratch my head and wonder "what is this thing"? This applies both to library functions and code from colleagues. Sometimes it feels like untyped languages are write-only languages.
This is my biggest gripe, too. Discipline about commenting helps, but only so much.
In my case, I have Clojure spec or the JavaScript equivalents at the important boundaries in my code. That makes this issue much less painful and also solves a few other issues to boot.
To be honest, in more advanced type systems, I’d ask: “What is this” only to be shown a convoluted type signature. I then put a println or breakpoint in there just like I would with a dynamic language and poked around.
