Comment by mjan22640

Programming is applied algebra, the choice is not using vs not using, but understanding what you are doing vs being ignorant about it. Relevance is in the eye of the beholder. In typical business the incentive is to have a good enough code ready "yesterday", and it will be thrown away tomorrow, as the code and whatever it does are only a means to generate profit and not a goal in itself, and spending time on making it profound is a waste. Wrt production examples, anything written in haskell used categorical constructs explicitly.