Go through a long complicated interview process only for them to ghost after multiple follow-ups. Very unprofessional and not considerate of a candidate's time (taking time off of work to go interviews, the multiple interviews, prep time, time taken to do the writing assessments, etc.) I think if a candidate follows up more than once, take 60 seconds to send an email back and give them peace of mind. You owe them that much after you spent 2+ months interviewing them and working with them.