In this AWS re:Invent 2023 session, Tod Golding explores strategies for building cost-optimized multi-tenant SaaS architectures. He emphasizes the importance of thinking beyond basic auto-scaling to create efficient, scalable systems that support business growth. Golding discusses key concepts like aligning tenant consumption with costs, improving operational efficiency, and understanding workload variations. He covers various architectural approaches, including pooled and siloed resources, serverless computing, and pod-based optimization. The talk also touches on the challenges of right-sizing storage and the importance of measuring and monitoring costs at the tenant level. Throughout, Golding stresses the need for architects to consider the broader business implications of their design choices and to continually seek ways to improve cost efficiency as the SaaS business scales.