You're lucky enough if you can find a developer who knows mutable data structures outside of SF. If you want immutable ones you need to add a zero to their wage.
> You're lucky enough if you can find a developer who knows mutable data structures outside of SF.
That's one of the most arrogant statements I've read on HN in quite a while.
Nearly all developers know mutable data structures, it's bread and butter. Immutable ones aren't some exotic life form, it's just that using them effectively (read: efficiently) as mutable ones can be really tough, and leads to more complex code.
I am out of SF. The number of times I've seen people start trying to parse XML with regular expression tell me all I need to know about their ability to code.
I've had random interns enter a purely functional codebase with 0 FP background. With a normal amount of onboarding, they were using immutable data structures with ease.
Most shops aren't prepared for that.