I had over 5 hours of interviews, several rescheduled, completed an extensive challenge, and was then ghosted. When I emailed to thank them and see what I could improve on - they ghosted again. Extremely strung along and told it was between me and one person and they ended the process saying their CIO was "sick that day" and they couldn't decide. They had obviously offered the position to the other candidate and not had the character to tell me (even a week later).