This whitepaper outlines the AWS Well-Architected Framework specifically for Software as a Service (SaaS) applications. It examines how to design and deploy multi-tenant SaaS workloads using AWS services, detailing best practices in operational excellence, security, reliability, performance efficiency, cost optimization, and sustainability. The whitepaper explores various architecture models like serverless SaaS, Amazon EKS SaaS, and hybrid deployments, focusing on the importance of tenant isolation and the complexities of managing and scaling a multi-tenant environment.