at least when using the Spring Boot integration, both artifacts are dependencies, but camunda-engine-rest-jaxrs2 seems to have all the classes of camunda-engine-rest-core packaged into itself (without changed package like at repackage steps). Therefore, both contain the same class files and you end up with duplicate class files. camunda-engine-rest-core should be rather a dependency to the camunda-endine-rest-jaxrs2.

I assume this to be an error with the assembly configuration.

• camunda-engine-rest-jaxrs2 gets pulled in by camunda-bpm-spring-boot-starter-rest (at least)
• camunda-engine-rest-core gets pulled in by camunda-bpm-spring-boot-starter-web (at least)