Build plugins influence the build process itself (e.g. compilation, code generation, packaging) and, unlike normal dependencies, are not transitive, i.e. they are not used in another project.

This is “only” possible in a multi-module project. The build plugins are declared in the parent pom.xml and then apply to all submodules.

Depending on the type of application and architectural design, I would recommend a multi-module project for microservices anyway. And the apparent need for a common module is a further indication of this for me.

May have a look at this article which gives you a good starting point: https://medium.com/@balachandar.gct/multi-repo-mono-repo-multi-module-repo-and-multi-module-mono-repo-architectures-a5a81613d522