This lecture covers the design of composite materials and structures across different scales, focusing on physical and data-driven models. It discusses the analysis models at various length scales, uncertainty quantification using data-driven models, and important innovation drivers in the aerospace industry. The lecture also explores simulation approaches, certification of composite structures, and micro-mechanical analyses. It delves into strain gradient hardening, longitudinal tensile failure, and optimization of the microstructure of hybrid composites. The presentation concludes with insights into size effects, meso-mechanical analyses, and the use of machine learning for uncertainty quantification.