I assume since no-one has mentioned Google+ in connection with Google App Engine, that is not built on top of it. Sure Google+ probably shares infrastructure w

I assume since no-one has mentioned Google+ in connection with Google App Engine, that is not built on top of it. Sure Google+ probably shares infrastructure with GAE, but you would think that if Google were really serious about GAE they would use it for their own external products. It sends a mixed message to the market when they tell app developers to use a technology for mission critical apps that they are not using themselves.