About 4 million lines of Python code is just a bad decision from the start. Now they are trying to fix it with types, but IMHO the fault is not in the language. They just should have started out with a statically typed language that scales better.
Yeah, I'm sure Dropbox's founders remember and regret that fateful day when they said to each other, let's write 4 million lines of Python to get this fledgling business idea off the ground!
