Learn how to add authentication and dynamic actions to Gatsby sites using Netlify Identity and Netlify Functions in this comprehensive tutorial. Explore the process of setting up authentication with minimal configuration, and discover how to send requests to a database using serverless functions. Follow along as Shawn Wang demonstrates the implementation of Netlify Identity for quick authentication setup and teaches the use of lambda functions for database interactions. Gain insights into topics such as Netlify Functions pricing, storage options in Netlify, Reactant Identity Widget, importing and resetting identity, deploying and testing identity, creating environment variables, and updating Gatsby. Access the provided GitHub repository and demo site to enhance your learning experience.