Hence if I ever get money for an infrastructure pentest, I want to include a scenario that scares me a bit: The hijacked application server. The pentesters give me a container with whatever tooling they want and a reverse shell and that gets deployed in the dev-infrastructure, once privileged and once unprivileged, both with a few secrets an application server would have. I'd just reuse a deployment config from some job. And then have at it.
And yes, this will most likely be a mess.