The Staging Environments
The QA/Staging Environment is shared by all developers, product owners, and quality assurance personnel. It’s not intended for public consumption.
Continuous Acceptance Testing
The ease with which it is possible to deploy to the staging environment(s) means that product owners and QA personnel can follow the development of features in an agile way. Hence, acceptance testing is a continuous, active process rather than a last-minute one. This kind of pipeline – with a staging environment and manual acceptance testing – really is Continuous Delivery rather than Continuous Deployment.
Not a Sandbox
A staging system is not ideal for fulfilling the role of a sandbox environment for external developers developing client software using your APIs. The reason for this is that sandbox environments need stability of features and properties, whereas the purpose of staging environments is the evaluation of something that’s changing continuously.