This document discusses optimizing Gatsby sites for production. It introduces Gatsby and its phases of development including development, staging, and production. It then discusses several plugins that can be used to optimize Gatsby sites including plugins for adding sitemaps to improve search engine indexing, embedding videos and images, supporting markdown pages, and generating RSS feeds to make site content easily subscribable. For each plugin, it provides the plugin name, how to install it, and what it is used for.