We can have a connective layer of logic that lets us write code to connect and extend cloud services by using Cloud Functions. Examples are listening and responding to a file upload to Cloud Storage, a message incoming on a Cloud PubSub topic, or an update made in a log.
Cloud Functions increases existing cloud services by allowing you to address an increasing number of use cases with subjective programming logic. A Google Service Account credential is already held by Cloud Functions to access services, thus making Cloud Functions work flawlessly with the majority of Google Cloud Platform services, such as App Engine, Cloud Storage, and many others.