> Was it simply aggregating results of multiple requests?
Pretty much. The company I was at was an early proponent of microservices so we had to have a service that operated as our entry point to all of it. Thats easy enough, but layering on versioning of the APIs for native apps on different platforms added complexity that definitely didn't seem worth dealing with in our at the time REST paradigm. We did have frameworks that generated clients for different platforms against that API so I'm not even talking about the boilerplate of sending and parsing JSON.