App Engine, seems to be no longer developed, and is considered “old” technology, it works, but its hard to do more enterprisy stuff, like virtual private cloud (VPC) with it. For example you can configure it to be able to access a VPC, but you cannot put it “inside” the VPC so others services can interact with it.

Cloudrun seems to be the new hot thing, and it works too, seems to be made using kubernetes itself, so promises future development and integration. However there is a tiny flaw in the system, berried in a fine print in an obscure doc page. Cloudrun severely throttles cpus on any containers that are not currently processing an http request. So you cannot build anything that is long running - kafka consumers, batch processes etc. What you are supposed to do is delve head first into the whole of GCPs ecosystem and embrace their queues, message brokers, and event sourcing systems (as they’re all http request based), woe to the ones that have to interact with tech thats outside of it.

/rant