I totally disagree. I think not having static types is a drag on productivity and maintainability. I have to work with both Kotlin and Ruby codebases, and the Ruby ones are always a nightmare whenever you need to make a change deep within the application's core, even though the Ruby one has more extensive tests.

The idea that test coverage is a replacement for static types is nonsensical. I won't insult your intelligence and say that by great test coverage you meant testing the shape of your inputs, because only an idiot would say that would serve as a replacement for something that is done automatically by a compiler, but sometimes minor naming mistakes (like `job` instead of `jobId` when you're passing an ID and not an instance of `Job`) will make it past code review and will place a totally unnecessary mental burden on the next programmer who has to look at the code and figure out what exactly he's looking at. With static types there is no need for that, it's right there in the code.