I scheduled an introductory interview. After scheduling initially I was asked the day before the interview to move the time up 30 minutes, and I did so. At the time of the interview, I never received a call. I reached out to the person I scheduled the interview with via email, and received a response about an hour and a half later that she had to step out of the office and asked if a time the next day would suffice. It's one thing when something comes up and an interviewer proactively reaches out to reschedule, it's an entirely different (alarming red flag) when you need to follow up after being ghosted by an interviewer. Safe to say I did not schedule that interview for the next day, and have since moved on with my job search.