Every modern application, whether SaaS, API-driven, or AI-powered, requires a robust authorization model to ensure secure access control while balancing security, flexibility, and usability. Planning an authorization model involves understanding the difference between authorization models, which determine access rules, and authorization architecture, which implements these rules through system infrastructure. Key considerations include defining what resources and operations need protection, understanding the diverse types of users interacting with the system, and establishing who manages and authors policies, which should involve stakeholders beyond just developers. Access decisions should account for dynamic contexts and external data, going beyond static roles to include approval workflows and complex business logic. The system must also handle auditing and compliance by logging access decisions and ensuring regulatory alignment. Future-proofing the authorization system is essential to accommodate evolving user types, complex business logic, and tightening regulations, which can be achieved by decoupling policies from code and supporting dynamic evaluation. A well-planned authorization model and architecture enable secure, scalable, and adaptable access control that aligns with real-world application needs.