Role-based User Access Control System

I need an access control system that's structured based on the roles my users have, similar to the old system.

Key Requirements:
- I need the system to manage user permissions on an individual basis. This means that each user should have unique permission settings.
- The system doesn't need to have options for temporary or time-based access permissions.

Ideal Skills and Experience:
- Strong background in access control systems.
- Experience implementing role-based access control is essential.
- Proficiency in customizing user permissions on an individual basis in a system.