Can a Flex application be completely private?

[Parth Mishra]

Is it possible to create a flex application that is not public facing at all but is available to all internal resources? It seems like App Engine will always expose a public endpoint which means I can't access it via internal resources that are located in private VPCs, correct? Would it be better to use a Kubernetes cluster?

[Jordan (Cloud Platform Support)]

You can restrict the access to your App Engine application via Firewall rules. Note the way to allow other App Engine services to access your application if this is required by your application.