This course provides security engineers and architects with a comprehensive framework for designing defense-in-depth security architectures on AWS. Rather than focusing on individual service configurations, learners design holistic security postures that integrate preventive, proactive, detective, and responsive controls into layered architectures that protect production workloads at scale. The course runs a single failure-mode throughline (how each control layer fails and what the next layer catches) and a running scenario (a fictional company, Northwind Analytics) so the layers build into one connected system rather than a set of isolated services.