A colleague pointed me to an interview with Google’s vice-president of engineering, Urs Hölzle. It may not have much new in it but is a good overview. I was struck by the following paragraph:
The job is not helped by the nature of the Web. "In academia," said Hölzle, "the information retrieval field has been around for years, but that is for books in libraries. On the Web, content is not nicely written — there are many different grades of quality." [The magic that makes Google tick: ZDNet Australia: Insight: Software]