This video from AWS re:Invent 2023 explores building serverless SaaS architectures on AWS. The speaker, a senior solution architect, discusses how serverless SaaS can help software vendors save costs, modernize legacy code, and increase operational efficiency. Key topics covered include the fundamentals of serverless services like AWS Lambda, API Gateway, and DynamoDB; multi-tenant architecture patterns; handling authentication and data isolation; asynchronous processing with SQS and EventBridge; and strategies for migrating existing applications to serverless SaaS. The presentation uses a fictional restaurant management software scenario to illustrate concepts and best practices for building scalable, cost-effective serverless SaaS solutions.