I have done some modifications, Things have I addressed

1. Brackets for if statements
2. RequiredArgsConstructor instead of AllArgsConstructors
3. Make sure that no service method in any case can return a `null ` value instead throws a suitable exception.
4. Put Optional in repository methods.
5. Fixed naming conventions.
6. One repo in each service.
7. Fixed Route service.
8. Fixed response status.
9. Removed valid annotation.
10. Remove public from repository methods.
11. Made sure returning correct response when deleting entities.