[jerf]

If I never again in my career have to encounter the God Function that everything in the system calls one way or another and takes 9 arguments, all of which are something like "either a string identifying an ID, or a function yielding a string, or a function that yields a list or an iterator of strings, or an object with a GetID method, or if the third parameter was falsy, a function to be called if the user is not authenticated", I will be pleased. Or the function that has literally 40 parameters, 36 of them optional, and while each of them may be individually reasonably well defined you will never work out what all combinations of them do, and you can also know there is no test and no spec for all possible combinations. (Unlike the former which is characteristic of local codebases and bad discipline, the latter is the basis of major dynamic scripting language libraries.)

Dynamic typing doesn't have to get that messy, but it takes discipline that is very hard to enforce at scale. Static typing can sort of approximate that level of mess but it takes a lot more work, and perhaps even more importantly, it's a lot safer to fix. But every significantly-sized dynamic scripting code base I've encountered has certainly had at least one of those two issues deeply, deeply ground into it.