Marcia Villalba, an AWS Developer Advocate, gives a presentation on serverless architecture using AWS Lambda. She discusses how serverless allows developers to focus on business logic without managing infrastructure. Lambda runs code in response to events and scales automatically. The document then provides a simple example of building a "hello world" API using API Gateway, Lambda, and DynamoDB. Code is deployed via SAM and the API is tested with Postman. Finally, the backend is integrated into a website.