Let's revisit the ID Card System. Imagine a large corporation with multiple zones (e.g., different buildings, restricted areas within a building like server rooms, or even parking lots). Employees need to use their ID cards to access these zones. The system needs to be robust, secure, and easily extensible to accommodate new zones, card types, and access control policies. We're not building the physical card readers or door mechanisms; we're focusing on the software system that manages the cards, zones, employees, and access rules. We'll need to handle scenarios like temporary access grants, lost or stolen cards, and different levels of clearance for employees. Think about designing a system that can handle thousands of employees and numerous zones efficiently. Consider the implications of concurrent requests for access and how to maintain data integrity. This is not just about allowing or denying access; it's about logging access attempts, auditing, and providing a framework for future integrations (e.g., integration with a HR system).

Requirements