Outpost interview questions

Wonderful experience that resulted in a verbal offer with details confirmed over email. Had a positive interview with the CEO and enjoyed the time speaking about the role and company. The recruiter had reached out via LinkedIn and was solid. Overall it was one of the most exciting opportunities I have been approached with!!! They said they would like to move forward ASAP at the end of the interview on-site and would follow-up. The next week there was a call with the CFO which included him talking and not letting me speak much, probing about my previous positions asking if I left on bad terms. The next day an email regarding start date and confirmation of that start date was sent by him, the CFO requesting I start earlier than the agreed upon start date. They said an offer letter was going to be sent "ASAP". I had not heard anything all day and reached out and was told not to worry. I was worrying. Something did not feel right. A day later and silence still after being told they'd get back to me by morning with the offer letter. The next morning I followed up again and was told the offer was withdrawn. This was after verbally agreeing, having been communicating back and forth about start dates just the day before and having my references checked. I ended current obligations to accommodate their start date request which was less than a week later, as this was an opportunity I was not only excited about but planning on a long term commitment. Ultimately the experience was one of the most unpleasant and shocking experiences, as I have never experienced something like this. That said, wonderful CEO and Head of Talent. I would question what went on during those last few days and how the decision was so drastically changed where you tell candidates who have made important changes to work with you that their offer has been withdrawn.