Google Cloud Platform for Developers

GKE or App Engine Flex

If you look at what's provided by GCP, as well as each service's features and functionality, GKE and App Engine Flex are very similar in what they do as well as how they do it. For instance, both platforms deploy container images from Container Registry to Compute Engine Managed Instance Groups and expose workloads through a GCP load balancer. You will also see that the configuration paradigms are very similar for each service.

This is the underlying Compute Engine Instance Group supporting an active GKE node pool:

The Compute Engine Instance Group supporting an App Engine Flex deployment would look almost exactly like ...