This is great stuff. In particular, how they designed their service interfaces to reduce coupling and allow instrumentation is really interesting. I'd love to s

This is great stuff. In particular, how they designed their service interfaces to reduce coupling and allow instrumentation is really interesting. I'd love to see more information on the faceted services - I wonder how using a particular facet of an interface affects the wire protocols (i.e. does it just expose a reduced set of methods or does it also affect which data are sent on the wire?). Amazing that they use memcached so much as a K/V store too, it's not something I'd have considered as a general store.