To answer your question with a few details about Telerik AppBuilder and Telerik Backend Services.
AppBuilder allows you to use a few different approaches when working with project files with integrated sync in the cloud or working locally. Yet you will be able to compile and build via AppBuilder (Code services) and also publish your app.
For your purposes you may consider the Visual Studio extension, Sublime text plugin or just the CLI with your favorite text editor or IDE. You can read about more about each of the choices here
As for Telerik Backend Services - these services does not have a relation to the way you are working with your code or project and does not allow to save or sync your project files or to compile and build your project. They are able to provide further functionality to your app by additional services like storing images, saving data in the cloud, offline data sync, push notifications, etc. More information about them here
I hope this answers your question.
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