If you were evaluating a system design for anti-patterns, you might look for the following characteristics: significant amounts of global, mutable data with a very high update rate requiring ACID semantics serve application data with no natural sharding (i.e. partitioning) dimension data storage-level hot-spotting interactive latency requirements for a global base of users These undesirable characteristics in your system, however, are precisely the desirable characteristics of your application! They form the basis of critical features needed for any successful Social network, and many socially-enabled applications. Come and hear about the tradeoffs explored and design idioms we discovered as we built Google's Social infrastructure.