Ridecell Engineer interview questions

It was by far the worst experience I have had. I met with a few people. One of the interviewers was not on my list of interviewers shared prior by HR, which is fine, but unexpected. After that person I was expecting to meet with two other individuals or at least one more if this person took over someone else's spot. He left and had me sit in the conference room for a while. Then a junior level HR person came in telling me he was looking for my next interviewer but couldn't find him. All HR people were gone and he was the only left and said he did not know what to do. I sat there for maybe 20 minutes when he came back to tell me that I may leave now. As I walked through the hallways, the building was empty, it was barely 5 pm. Either there was an emergency and everyone but the two of us evacuated the building or people leave pretty early for a start-up. Regardless, even if they did not want to continue on with the interviews with me...some professional courtesy and a good-bye would have been nice. And I have yet to hear back from them...again, at least send an email thanking me for my time.