Keycloak is a widely-used open-source tool for managing identity and access control, providing authentication and authorization features, though its built-in permissions system may not fully meet the needs of modern applications requiring complex access control. Implementing effective, scalable, and secure authorization using Keycloak involves understanding its three-phase authorization flow: validating tokens, making decisions with its policy engine, and enforcing resource access. While Keycloak supports role-based and attribute-based access control, it lacks more advanced models like relationship-based access control (ReBAC), which can be addressed by integrating external systems such as Permit.io. This integration can enhance Keycloak’s flexibility by decoupling authentication from authorization, enabling fine-grained access control, and simplifying policy management for multi-tenant applications. Although Keycloak is suitable for simpler projects, its monolithic architecture and static design can pose challenges for dynamic, high-performance applications, making external tools necessary for achieving more nuanced and scalable authorization solutions.