One screen Interview Scheduling and One Interview Notification
Users should be allowed to create /schedule/reschedule/cancel the interview from one screen, where they can add time/date/place/interviewers for all the interviews to be scheduled for a person.
When all the interviews are scheduled, only one single notification should be sent to candidates with all the details of all the interviews rather then sending multiple notification for each interview scheduled. It may happen that a candidate misses any one notification and misses out the scheduled interview. So a single notification is beneficial.
All the interviewers should receive their own respective interview notifications.