[crb]

Thousands of internal Google apps (most of the important ones we use day-to-day) run on App Engine. Many external apps do too - https://plus.google.com/107043289104010976501/posts/VYybt1BC... talks about developers.google.com, for example.

That doesn't help though, as Googlers learn to write apps the Google way (massively horizontally scalable, managed NoSQL data service), which looks very much like App Engine. Outside, people still wanted to run their relational databases and large VMs, and App Engine didn't let them do that. That's why we came out with Compute Engine.