I heavily prefer strictly typed languages once the code base exceeds a certain size

As do I, but we don’t all get to pick our stack.

I use Rust for all my personal projects unless I have a good reason to pick something else. I like pretty much everything about it, from the lack of classes (I hate massive class hierarchies) to the borrow checker to everything being an expression. It feels like I’m getting most of the benefits of functional programming, without being tied down to FP to solve problems.

That said, I think Python is a reasonable choice for large codebases. For simple scripts, I generally don’t bother with type hints. At my current company, our largest codebase is well over 100k lines of Python, so the type hints are absolutely welcome since they help document code I haven’t touched in over a year (if ever). If things get slow, there’s always the option of a native module. But for most things, Python is fast enough, so it’s no big deal. Because of this, I use type hints for anything that might become a larger project. After the initial POC, I’ll go through and update types, fix a bunch of linting warnings/errors, and flesh out the unit tests. That way I have something to build from when I inevitably come back to it in a year or so.

So yeah, I definitely recommend using type hinting. The best time to add type hints is at the start of development, the next best time is now.