Walk Score makes heavy use of GAE across many of its products, and is very happy with it. Despite the occasional downtime, the price/performance is on par with

Walk Score makes heavy use of GAE across many of its products, and is very happy with it. Despite the occasional downtime, the price/performance is on par with needs. Walk Score uses AWS where it needs heavy compute back-ends, but all front-ends (including API "front-ends") are GAE-based.