Hello Julian, well for the CoreModule you can have your custom modules too of course the auth module is a perfect candidate for the CoreModule, just be careful not to put the authentication components (login form, etc..) The CoreModule is supposed to host mainly singleton services then in some particular cases some singleton components. For the SharedModule, you are totally right, angular material is a perfect candidate here too, just don’t import all the angular material modules but only the ones that are used widely in your app. Don’t feel ashamed to bring your specific angular material modules into the feature modules. For example, when you import an angular material module more than 2 or 3 times in your app, then you can think of putting it in the SharedModule. Happy coding ;)