This document discusses various patterns for horizontally scaling an AEM implementation. It begins by defining performance and scalability, and notes that pre-Oak scalability patterns are covered. Eight common use cases for scaling AEM are then described and solutions proposed: 1) high volume delivery, 2) high frequency input, 3) high processing input, 4) high volume input, 5) many editors, 6) geo-distributed editors, 7) many DAM assets, and 8) geo-distributed disaster recovery. For each use case, one or more solution patterns are outlined in one to three sentences.