I attended the 2014 American Control Conference in Portland, Oregon. On the right is a photo of the iconic Mount Hood taken outside the city on I-84. At the conference, I spoke at the workshop entitled “40 Years of Robust Control 1978 to 2018”. Chris Meissen also presented the paper “Performance certification of interconnected systems using decomposition techniques”, co-authored by me and Andrew Packard. The paper describes a framework for analyzing interconnected systems. Performance certification is typically a difficult problem that scales poorly. The approach we propose uses a distributed optimization technique to find a global performance certificate by only ever solving local certification problems. The approach is very fast and scalable, but it is only sufficient in the sense that it may fail to find a certificate even if one exists.