This is demo code showing how the memento pattern can be used to keep domain entities completely separated from persistence concerns when using entity framework core (efcore)
To keep the code lean and as specific to the problem as possible some of the common persistence patterns such as the repository and unit of work patterns are not part of this sample. Also, the command/query handlers in the app are only roughly implemented.
And that's all OK. It's sample code, after all. 🙂