Four interviews including HR, all seemed unprepared and the interviewers seemed miserable. Despite this I was given an offer. The offer letter lacked basic details such as bonus structure, benefits etc. and also included a six month probationary period. I asked for clarification on these points and more, which took them 9 days to provide despite the offer letter saying 'details available immediately upon request'. After getting my answers I was given two days to accept or decline the offer, then the next day they rescinded it saying they needed a 'candidate that better suited the culture of the company' (despite already giving me an offer). While I waited for clarification on the points I even provided my references and background check info even tho I didn't have to, in good faith and to show my willingness to keep the process moving. The firm they outsource this stuff was incapable of contacting my former employers so it came back to me to dig out old ROEs to provide them. They also reached out to my references with a very long questionnaire with details that were difficult to recall - turned out to be a significant demand on their time. All told I probably spent about 5 or 6 hours on this just to have them rescind it on a whim without even an email or phone call from HR or the hiring manager.
Easily the most unprofessional experience of my career. Do not trust these people.