This post to me reads like the author has given up on defining contracts between systems. While I think it's useful to be able to exercise a system for real, I

This post to me reads like the author has given up on defining contracts between systems. While I think it's useful to be able to exercise a system for real, I generally prefer to do it in production rather than attempt (and fall short) of reproducing production in an isolated environment. Meanwhile, I'll invest my time in defining and understanding the contracts between services, and develop against those contracts so I don't have to run the entire stack of connected pieces every time I want to make a small change.