A Multi-module Maven Project is a software architecture pattern that allows developers to split a large project into multiple interconnected sub-modules, all managed by a single parent project.

This parent-child Maven structure aligns well with microservices architecture. For example, a parent project can contain gateway and auth-service sub-modules. After packaging, these two modules can be deployed and maintained separately.

It’s important to note that this parent-child relationship is for build management, not a functional hierarchy. The parent POM centralizes dependency management, but it doesn’t mean gateway necessarily depends on auth-service.

Programmatic Dependencies: If the gateway module needs to use classes from auth-service, you would add a dependency in its pom.xml. However, in a typical microservices setup, gateway and auth-service communicate via HTTP APIs or OAuth tokens, eliminating the need for a direct JAR dependency.

A typical multi-module project structure in Maven looks like this:

workspace/
 ├─ pom.xml           <-- Parent POM, defines dependencyManagement, pluginManagement, versions
 ├─ gateway/          <-- Child module
 │   └─ pom.xml
 └─ auth-service/     <-- Child module
     └─ pom.xml

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