The Immutable Artifact with Variable Coordinates

This has to do with immutable/versioned software artifacts, such as a versioned Jar file. The idea is that you build your artifact and publish it somewhere and everywhere it is deployed - you use exactly the same artifact. This way when you test your sofrware in staging environment - you can be sure it is the same software that is deployed in production.

The irony comes into play when CI/CD meets business requirements. In order for an artifact to get ready to be deployed it needs to go through multiple steps of verification process, quite reasonably. While these steps often involve "promoting" an artifact from one environment to another, and sometimes, since all this was needed "yesterday" - sometimes this also means building the same artifact in multiple environments, since the build process is well understood, and you can just copy and paste the build part of the pipeline. In this case you also do not have to argue with everyone about what exactly it means "to promote" and artifact from one place to another. These meetings usualy start with unnessesary long explanation of what an "immutable artifact" is, so by the time the meeting is done - you're still at square one. So the outcomes of such operations is often having a copy of immutable artifact in multiple places (variable coordinates), sometimes it is not even the same artifact, there goes the "immutable" part, even though it carries the same version. Hence the ironic name.