That part is a a little more nebulous. When deploying the entire full stack of all applications is automated, rolling a new environment is very simple. So, for instance, if I wanted to load test a specific end point in our API, I would just build a new instantiation of the API and test against that in a protected and isolated environment.

So in reality, it might be 2 staging environments and 12 testing. There was no real set number of environments.