Yeah, +100 I have this same problem in general. FWIW, the only real practical example I've seen (which has been rather serendipitous for me) is the "Seven Sketches in Compositionality" linked in the comments below applying category theory to databases. You can even play with the actual an implementation (written Java) to see some real world code here: https://github.com/CategoricalData/CQL Dunno if that helps your needs much but it was at least some kind of concrete starting point for me.