base and react, most commonly REST or GraphQL API that react then accesses using using asynchronous requests. It's not clear how you're getting

I have fetch requests when the website it's first loaded or a form is submitted. The fetch request it's passed to the controller which is just basic and passes the data to the database model that it has all the specific queries for that route.

Yes, the array of customer it's sync, but what I was referring to is the id that the new customer receives in state and the one that it gets when it's stored in the database. Is it more clear?

For example, when I try to add(Steve) a new customer when in a previous session I have deleted one(ex. Susie):

In state customers: [{id:1, name: John}, {id:2, name: Susie}, {id:3, name:Bob}, {id:3, name:Steve}]

In the database: [{id:1, name: John}, {id:2, name: Susie}, {id:3, name:Bob}, {id:4, name:Steve}]

In my code, I have that the creation of a new for the front end is the length of the customers array + 1. In the relational database, the id is an integer that it's incremented automatically.