I am investigating AWS API Gateway and I keep seeing that you can use it to “aggregate the results from multiple old-school RPC-style web service calls into a single response”.
However, I cannot find anything on how to achieve this.
I have looked through the Method Execution options but only see how to define a single endpoint URL.
Is aggregation only possible using a lambda function or is there a way to configure data aggregation within API Gateway?
I believe you are referring to Amazon API Gateway – Build and Run Scalable Application Backends
This type of aggregation is possible, but you would need to implement it, according to your requirements. It is not a feature of the service per se, but the service allows you to implement that, if you desire.
The point that they are making is that with a new single API call that you implement, you could then aggregate the results from multiple old-school RPC-style web service calls into a single response.
The implementation is up to you.