I feel like this is the same argument that people give when trying to justify not writing tests. Tools like type-checking and automated tests aren't a magic for

I feel like this is the same argument that people give when trying to justify not writing tests. Tools like type-checking and automated tests aren't a magic forcefield that will shield you from any and all runtime bugs. But they do protect against a good percentage of them, and as another commenter pointed out...70% type-checking is better than 0% type-checking. The point of type-safety is to be able to describe more succinctly what the _programmer_ expects out of the code. As you said, when you get to production, "all bets are off". This still applies with any type-safe language. Types don't exist when you're compiling to machine code, either.