In this AWS re:Invent 2023 session, Heitor Lessa and Ran Isenberg present a comprehensive guide for pragmatic serverless Python development on AWS Lambda. They cover project structure, Lambda handler implementation, business logic organization, integration practices, and testing strategies. The speakers emphasize the importance of context-driven decision-making and introduce open-source tools like Powertools for AWS Lambda, PyTest, and Pydantic. They demonstrate how to build both synchronous and asynchronous APIs, highlighting the differences in approach and testing methodologies. The session also includes practical advice on profiling and optimizing Lambda functions, using tools like Tuna and PyInstrument. Throughout the presentation, the speakers stress the importance of maintainable code, effective testing, and production-ready practices. They conclude by offering resources for further learning and a template for implementing these practices in real-world projects.