Three-Step Lifted Interfaces

This is a wonderful elaboration of something that senior engineers do effortlessly and that junior engineers often struggle with. The writing is clear and the diagrams help make it even more so. I foresee that I will be sharing this in PR reviews in the future!

Strongly statically typed languages let you safely refactor in ways that would otherwise be risky. This is my trick for one very common example: lifting an interface out of a concrete type.