SERES Software Engineer interview questions

A seres recruiter called me to schedule an interview. 1 minute before the interview time, she called and said they had to cancel, and reschedule the next day. I said, fine. The next day, at the interview time, there was no phone call. I waited 5 mins, 10 mins, 30 mins...nothing. I reached out to the recruiter to politely ask if the interview was still happening. No response. Unprofessional! Don't bother applying here.