Recruiter emailed for initial phone screen with him so I sent him my availability. He did not follow-up with a confirmation so I emailed him 24 hours later to follow up. Still no response. Then I resubmitted my availability through his Greenhouse calendar link. That's when he finally responded. On the day of the interview, I had to reschedule due to a school issue that took longer than expected. He said no problem. So, I provided him with my availability. Two days have gone by and still no response from him. At this point, I am just going to assume that he is not interested in my candidacy. This is a huge red flag when a recruiter can't even follow up.