Design an Attendance System

Requirements: Design an Attendance System with:

1. Different roles (teacher, dean, student, etc.) with different views per role.
2. Teachers and students both opt into courses; track and display student attendance per course to both students and teachers/deans.
3. Students should see how many more classes they must attend to reach 75% attendance.
4. Additional features as needed.

Also design the LOGIN system for the same and explain how it works. Show DB structure, APIs, and logic.

Design: Cover a DB schema (Users, Roles, Courses, Enrollments, AttendanceRecords), REST APIs for marking/viewing attendance, the running attendance-percentage calculation and classes-needed-for-75% logic, and the login/session design for authenticating and authorizing different roles into their respective views.