The emergence of serverless infrastructure and services represents a fundamental shift in how developers approach architecting applications. This is especially relevant in the world of SaaS, where systems must efficiently and cost-effectively respond to continually shifting multi-tenant loads and profiles. In this session, we dive into all the moving parts of a serverless SaaS application, exploring the detailed code, design, and architecture strategies that are commonly applied to support the complex scale and agility requirements of multi-tenant serverless SaaS environments. We also look at how serverless influences core multi-tenant strategies, including tenant isolation, service decomposition, management, deployment, and identity.