# Package hierarchy

The Go package hierarchy in Grafana should be organized logically (Ben Johnson's
[article](https://medium.com/@benbjohnson/standard-package-layout-7cdbc8391fc1) served as inspiration), according to the
following principles:

- Domain types and interfaces should be in "root" packages (not necessarily at the very top, of the hierarchy, but
  logical roots)
- Sub-packages should depend on roots - sub-packages here typically contain implementations, for example of services

## Practical example

The `pkg/plugins` package contains plugin domain types, for example `DataPlugin`, and also interfaces
such as `RequestHandler`. Then you have the `pkg/plugins/managers` subpackage, which contains concrete implementations
such as the service `PluginManager`. The subpackage `pkg/plugins/backendplugin/coreplugin` contains `plugins.DataPlugin`
implementations.