Event Sourcing (ES) is a software design that requires the persistence of events instead of results. In the Programming experience section of Chapter 1 , First Steps Toward Reactive Programming, we had the opportunity to understand how to persist data in a reactive way. Even though this is not mandatory using ES when programming reactive, this is the most natural way of dealing with data persistence from an observable sequence.
Tip
Talking exhaustively about ES is outside the scope of this book. We will assume the reader already has some knowledge about ES. Otherwise, here are some details: ES: https://msdn.microsoft.com/en-us/library/jj591559.aspx CQRS with Event Sourcing: https://msdn.microsoft.com/en-us/library/jj591577.aspx Further reading: Microsoft .NET: Architecting Applications for the Enterprise, 2nd Edition, Microsoft.
By implementing the ES design instead of persisting results at specific dates, we persist data exactly as we receive it from an...
