I think you overestimate the extent to which Google acts as a top-down, unified company.<p>It took about 5 years to get a single unified Google login.  It took another couple before every property supported multi-login.  GWT and Angular.js are both Google projects, but the vast majority of Google production services use Closure instead, and the Chrome team is pushing Polymer.  AppEngine is used extensively internally, but the largest public-facing service on AppEngine that I know of is Fiber, which is totally dwarfed by the largest external customer of AppEngine (SnapChat).<p>[At least, it was when I left in 2014; there was gonna be a big push into Cloud, so it&#x27;s possible several other services have rewritten on top of GCP.]