Backing services consist of any service the application consumes over the network for normal operations. This could be a third-party API service, an email system for notifications, a file store, or a database. Backing services often store state for a distributed application.
Carefully plan which backing services should be used with your modernized application. Since backing services store state data, they are more difficult to move to different clouds. Consider using backing services that are portable across cloud platforms to provide multi-cloud flexibility. For example, using a traditional cloud managed database offering might not be portable to a different vendor cloud’s database offering.
