In cyber-physical systems (CPS) computing, networking and control (typically regarded as the “cyber” part of the system) are tightly intertwined with mechanical, electrical, thermal, chemical or biological processes (the “physical” part). The increasing sophistication and heterogeneity of these systems requires radical changes in the way sense-and-control platforms are designed to regulate them. In this presentation, I introduce a design methodology whereby platform-based design is combined with assume-guarantee contracts to formalize the design process and enable realization of CPS architectures and control software in a hierarchical and compositional manner.