Is the function/bean you want to override is injected through Spring?
If no, and you need to override say some jar, class or xml. You have choice of ant customize
or buildcallbacks.xml
If yes, it's no different than overriding any other beans from parent extension. The only thing is that you will not need to create an extension dependency as platform is available globally.
For example : If you wish to override some function in DefaultCatalogDao to give your own implementation. You can do it like...
- Create your own implementation extending the platform related service
- Inject your custom bean with alias of the defaultCatalogDao
<alias alias="catalogDao" name="customCatalogDao"/>
<bean id="customCatalogDao" class="......CustomCatalogDao" parent="defaultCatalogDao"/>
For Commerce Cloud
You can change platform files using customize folder in Commerce Cloud V2 too. You would need to create a folder in your custom repository with name _CUSTOMIZE_
and then as you do in non cloud version, add your files (with exact folder structure as in platform).
Once you creare above folder, CCV2 build strategy automatically picks and deploys it, without any additional configuration.
Hope it helps!