Practical application of Cats : composing services

Ok. So the Typelevel Cats project looks interesting, but how do you apply it to real programming problems?

This video gets beyond the type / category theory and shows how to use cats.data.Kleisli and other Cats libraries to really change the way you code services. The ability to compose services is really very interesting.

https://youtu.be/urdtmx4h5LE

One of the concepts in this video that I needed to review was that of the Monad Transformer:

This blog entry explains Monad Transformers :

https://blog.buildo.io/monad-transformers-for-the-working-programmer-aa7e981190e7