[kerblang]

Since the specific question is "how do you keep track of", my build & deploy script copies a quick one-liner dump of git information (SHA, date, environment, branch, etc.) to a directory on a shared server, as a text file. Later I can go to that server and `cat versions/* | sort` to get a report of what is deployed where/when and so on.

It helps that I have One Deployment Script To Rule Them All (or really, a couple DSTRTA's). When every service has its own special build & deploy script you have to ask nicely and hope people keep up with it. A lot of CI/CD systems force you into that corner because of an implicit assumption that each build & deploy is its own special one-off.

Anyhow, text files rule, at least as an ad-hoc solution.