You need to test your service APIs. You may expand your application into a service API. Or, you may consume someone else's service API. How do you guarantee the behavior of your own service API? And how do you ensure that your application which depends on a third-party service API? Whether you develop your own service APIs or depend on others, learn to test your service APIs.
This imperative lies at the heart of the Test Automation University course, "Exploring Service APIs Through Test Automation," with instructor Amber Race (Twitter: @ambertests). We're offering courses like this to help engineers like yourself think about and improve the quality of your services through test automation.