In my previous post SharePoint 2013: Get UserProfile Properties with REST API, we saw how to fetch SharePoint UserProfile properties with the REST API.
When I wrote that post, SharePoint Online did not support REST API batching. Since then, it has been implemented and as a result we can get multiple Custom/OOB User Profile properties in a single REST call.
Here is my code showing how to do it:
Here are some other great resources on SharePoint REST API Batching:
Batch Processing (OData Version 3.0)
Part 1 - SharePoint REST API Batching - Understanding Batching Requests
Make batch requests with the REST APIs
Thanks for reading!