I have found optional typing to be a great example of an 80:20 trade off. I add type annotations to the easy stuff. I get a huge bang for that. I find that once

I have found optional typing to be a great example of an 80:20 trade off. I add type annotations to the easy stuff. I get a huge bang for that. I find that once I go past the “easy” annotations, I get less and less back from that. Between the IDE and my own annotations it catches 95% of trivial type errors.