The paper “Performance certification of interconnected systems using decomposition techniques” by Chris Meissen, me, and Andrew Packard was submitted to ACC’14 in Portland, Oregon! This paper proposes a framework by which one may certify the performance of an interconnected system. The main idea is to certify something about each component in such a way that we can deduce the desired property for the interconnected system. We also show that the Alternating Direction Method of Multipliers (ADMM) is a potentially viable algorithm for solving our optimization formulation. Scalability is a key feature; all difficult computations are done locally and possibly in parallel. The goal is to eventually apply our technique to interconnected systems consisting of a large number of nonlinear components, a task that is computationally intractable when the interconnected system is treated as a single large system.