Service Oriented Architecture: It's Time to Play Nice With Others! - Mike Willbanks

Chances are your application serves multiple purposes. It supplies data to a mobile application, it might supply data to a node.js application, it could be a backend only application and more. SOA (Service Oriented Architecture) is a necessary paradigm and pattern to build your applications in such a way to play well with others. APIs may be the ultimate part of the puzzle but designing your architecture in a service oriented way will help achieve building your API in a far quicker way.