In this comprehensive session from AWS re:Invent 2023, Ben Smith, a principal developer advocate at AWS, delves into advanced serverless workflow patterns and best practices using AWS Step Functions. He covers key topics including why to build with Step Functions first, the differences between Standard and Express workflows, cost optimization strategies, and extensibility patterns. Smith demonstrates how Step Functions can simplify serverless application development, improve visibility and debugging, and reduce costs compared to traditional Lambda-based architectures. He shares real-world examples and patterns like the REST CRUD API, callback pattern, and distributed Map state for high-scale applications. The talk concludes with recent Step Functions updates including Redrive, HTTP state, and Bedrock integration. Developers will gain valuable insights on leveraging Step Functions to build more efficient, scalable, and cost-effective serverless applications on AWS.