When building a SharePoint Framework web part - where are the property values of the property pane to be saved?

With add-ins and their tool pane, the options are: let SharePoint do it, use a hidden list, use a custom service (see Q&A [here][1]).

How is this supposed to be done with SharePoint Framework? Does SPO provide a means for saving and loading these properties?


  [1]: https://sharepoint.stackexchange.com/questions/197287/where-can-i-save-values-properties-in-a-sharepoint-add-in/