> I take it the datastore change is just an api change? (There isn't any data migration needed, is there?)

Yup!

> It looks like memcache is moving to a third-party service now instead of a built-in api. Is performance different? Does anyone have experience with this?

I'm not sure about the performance impact. But I can tell you that we're working with the Cloud Memorystore team to have a better memcache story for the App Engine second generation runtimes

Both google.golang.org/appengine/datastore and cloud.google.com/go/datastore connect to the same data? Is there a list of incompatibilities somewhere? I remember seing some serialization differences between these two datastore libraries.

You remember right - I think you might be referring to this issue: https://groups.google.com/forum/#!topic/google-api-go-announ...

> the cloud datastore package will default to writing your nested structs as entity values, while the appengine datastore packages will only write your nested structs as flattened sets of attributes.

Other than that, there are no differences.

(GCP Gopher)

Hi (App Engine PM here). Yes both libraries connect to the same database (Cloud Datastore). cloud.google.com/go/datastore is preferred as it uses the Cloud Datastore API instead of the App Engine specific API, so your code will be portable.

You are right that the devil is in the details, and there might be some slight serialization differences. I cannot find an exact list.

Feel free to post here if you need more help.