This book gathers the latest advances, innovations, and applications in the field of optimization-driven architectural design, presented at the 3rd International Conference on Optimization Driven Architectural Design (OPTARCH2025), held in Amman, Jordan, on December 18–20, 2025, jointly with conferences OPT-iii2025, ADDOPT2025, and DiGiCES2025. It covers topics such as optimization software, evolutionary algorithms and swarm optimization, robust design optimization and reliability-based design optimization, optimization in micro- and nano-mechanics, multiscale and additive manufacturing, multidisciplinary and multiphysics design optimization, multiple criteria decision-making and optimization, generative and parametric design, parallel and distributed computing in optimization. Written by leading researchers and engineers, and selected by means of a rigorous international peer-review process, the book highlights numerous exciting ideas that will spur novel research directions and foster multidisciplinary collaborations.