The Google Cloud Datastore Ruby Sample Code by Google demonstrates JSON architecture in requests and responses when interacting with the API. Examples allow developers to include credentials, service, and projectIDs.
There are now a number of backend-as-a-service companies focused on mobile developers. We list 6 backend APIs that help with common mobile tasks, including the Cocoafish API, which was today acquired by Appcelerator. But it's a much bigger ecosystem, as shown in the infographic below.
Handling API calls in the cloud with a service like AWS Lambda is one of the latest ways enterprises try to save on resources. In theory, you can save a ton of money. But be careful. Costs for API calls can mount up, sometimes leaving you with a cloud computing bill ten times the size you expected.