I've really embraced type annotation and mypy for Python. Partly because it really helps the Python language server in VS Code with autocomplete. It has also saved me a few times in pointing out some type mismatches and forcing me to really think about what I'm returning, etc. It also makes reading the code easier in terms of reasoning about it.
I've noticed this similarly switching to using typescript over javascript. I'm not a huge JS dev anyway so I don't use it much, but having type signatures to enforce requirements, but being able to turn them off when they get in the way is great for productivity. Of course in a productive environment I would probably enforce strictness of the types but for my own terrible front ends, I don't care
> It also makes reading the code easier in terms of reasoning about it.
For me that's huge. I work in a support role where I pretty much exclusively look after code other people have written. Without type hints when something blows up I need to follow the code all the way back to whenever the variables were initially substantiated so I can know what to expect and what I can do with it. If I have a type I know what I'm looking immediately and start building a model of things without back tracking.
