This resonates with me this so much. I feel like half the comments in this thread are missing the value typing, but maybe they've never had the misfortune of working with hundreds of other developers on a project with no defined contracts on aggregates / value objects outside of code comments and wishful thinking.

I've worked on large python codebases for large companies for the last ~6 years of my career; types have been the single biggest boon to developer productivity and error reduction on these codebases.

Just having to THINK about types eliminates so many opportunities for errors, and if your type is too complex to express it's _usually_ a code smell; most often these situations can be re-written in a more sane albeit slightly verbose fashion, rather than using the more "custom" typing features.

No one gets points for writing "magical" code in large organizations, and typing makes sure of this. There's absolutely nothing wrong with writing "boring" python.

Could we have accomplished this by simply having used a different language from the beginning? Absolutely, but often times that's not a option for a company with a mature stack.

TL;DR -- Typing in python is an exception tool to scale your engineering organization on a code-base.