As someone who works for Google (but is expressing his own opinion), most of what you're saying about Google seems reasonably accurate. One note:

> Google is very very large and very (for a web tech company) old. It has a lot of internal technology that's not available elsewhere and it's built to make it easy to build extremely large systems.

Please don't read this and get the impression that we have a lot of legacy code that just sits around. Our systems have a tendency to turn over very quickly, to the point where we joke that all infrastructure systems are either "beta" or "deprecated."