Residuality theory is a revolutionary new theory of software design that aims to make it easier to design software systems for complex business environments. Residuality theory models software systems as interconnected residues – an alternative to component and process modeling. It uses applied complexity science to make managing uncertainty a fundamental part of the design process. In this episode, we will discuss this novel approach with Barry O’Reilly, veteran architect. Barry will also do a workshop and a talk about this subject at the Software Architecture Gathering.