If you write a full infrastructure for deploying apps, monitoring apps, service-injecting apps, routing to apps on AWS, then you are probably using their APIs f

If you write a full infrastructure for deploying apps, monitoring apps, service-injecting apps, routing to apps on AWS, then you are probably using their APIs fairly heavily. All the IaaSes have APIs for fundamental components like compute, storage and network. BOSH provides a relatively uniform layer for them, which is how Cloud Foundry manages to get around to so many platforms.