Google App Engine (GAE) continues to provide a serverless app-hosting service with autoscaling properties, despite new features primarily going into newer serverless platforms. GAE apps using bundled services can now migrate from Gen1 to Gen2 with minimal friction and upgrade to recent language versions. Developers have options to stay on GAE, break up large apps into microservices for Google Cloud Functions (GCF) or Google Container Registry (GCR), or containerize their apps for GCR. Apps not using bundled services can be migrated to "serverful" platforms like Google Compute Engine (GCE) or Google Kubernetes Engine (GKE).

Source: https://dev.to/wescpy/hosting-apps-in-the-cloud-with-google-app-engine-3fn