"It is always tricky to schedule an interview with more than one interviewer. If I am not able to find a time on their calendars when both are available in the near future, I'll try to be creative to find a solution since making a candidate wait too long for an interview can result in them moving on to a different opportunity. If one of the managers is traveling, I might see if they are comfortable participating virtually in the interview. I have also had managers in the past recommend a proxy to fill in for them - perhaps someone else from their department or even their manager. Sometimes the only option is to see if something else on their calendars can be rescheduled to create an opening for the interview. For the right candidate, you do whatever it takes to get them in front of the hiring managers."