The guide offers a comprehensive tutorial on integrating Keycloak, an open-source identity and access management solution, with Neon's Postgres database and deploying it on Koyeb. It highlights Keycloak's capabilities, such as single sign-on, two-factor authentication, and support for identity protocols like OAuth 2.0, while providing step-by-step instructions for setting up a Keycloak database on Neon, creating a database user with specific privileges, and deploying Keycloak on Koyeb using container images. The guide also explains how to create and manage Keycloak realms and clients, exemplified by connecting a Next.js application using NextAuth.js for user authentication. It emphasizes the importance of configuring environment variables correctly and offers suggestions for optimizing Keycloak's performance in production environments, such as crafting an optimized container and exploring Neon's features for data restoration.