Implementing Role-Based Access Control in Spring Boot — Users, Admins, and Where the Line Gets Drawn

There's a moment in every backend project where "anyone can call any endpoint" stops being acceptable, and you have to actually decide who gets to see what. That moment hit me this week, and the answer was Spring Security with role-based access control (RBAC). Here's what I built: a registration system where a user can sign up as either a regular...