The Mac calculator's original design came from letting Steve play with menus

I'm not sure of the timing (and whether you're sarcastic) but yeah, I found it funny compared to PARC showing Steve Jobs how the Smalltalk environment allowing modifying GUI behavior at run-time let them iterate quickly, sometimes in front of users (https://www.youtube.com/watch?v=uknEhXyZgsg&lc=UgwYCZ7PefOXO...).

I guess https://www.folklore.org/Calculator_Construction_Set.html is the closest you get with a compiled language :-)

P.S. https://web.stanford.edu/dept/SUL/sites/mac/parc.html has good historical context on that visit(s)