I’m a little late getting to it, but Dan Catt’s writeup of “the [Guardian] Open Platform, APIs and Google App Engine” is well worth a read.
Dan explained some of the architecture to me over lunch during The Story a few months back and I was impressed by the way they’ve embraced a plurality of tools to build apps, and devised a caching infrastructure that will ensure their frontend is robust even if something doesn’t quite work out in an experimental piece of the system.