Like other commenters, I disagree there are diminishing returns to static typing itself, but rather diminishing returns to proper engineering in certain cases (

Like other commenters, I disagree there are diminishing returns to static typing itself, but rather diminishing returns to proper engineering in certain cases (i.e. do something as perfectly as possible). By adding types (and in the extreme, dependent types), you're allowing compiler to prove more things about the code (to check correctness or generate more optimal code). If you actually need to prove more things, then it's better to leave that for a compiler rather than human. Of course, if you're writing e.g. web scraping script, you don't need these guarantees and then you don't have to care about types. But the better engineering you want, the more static typing will help and there is no diminishing returns.