I was contacted by a recruiter after submitting an application online. I promptly used her calendar link to set up a time for an introductory call. A few minutes after our call was supposed to start, she texted to ask if we could reschedule to the next day. I said sure, no problem. The next day she failed to call and stopped responding to any messages with no clarification as to why she suddenly ghosted. It all struck me as extremely unprofessional.