We build distributed systems to maintain availability and improve performance. However, as soon as distributed state is thrown into the mix, you have to start thinking about the performance costs of accessing that state and keeping it current. Many of the worst problems concern the need for coordination across nodes and across systems within a node. Drawing on the lessons he’s learned working on Wallaroo, a high-performance, open source framework for building stateful distributed applications, I'll share strategies for avoiding coordination and relying on local knowledge wherever possible.