One nice thing about Visual Builder is that it helps you not only with the creation of the front end, but also with the creation of the backend for your app - through the use of the business objects feature. When you develop the UI in VB it is accessing the business objects through REST endpoints, and these REST endpoints can also be exposed so other UIs or systems can access the same data.
In the video below, I'm showing you how to access the business objects and perform the full set of CRUD operations against them.
One more note - in the demo I use the Bearer Token security, but you can also switch to use basic authentication to access your services. To do this in your application settings, under the business object tab, you can check the check box for enabling this.