Waste of time...
Very weird company. A lot of people on Glassdoor seem to dislike the CEO, and a lot of people that interviewed me implied that he does not know what he's doing, but I met him and he seemed fine to me. I thought it was odd that people were speaking negatively about their CEO during a candidate interview, and that should have been my first red flag.
I went through a few very lengthy rounds of interviews, answering all questions based solely on my experience. I felt very confident I would get an offer, but I was told that I would not because they spoke to a former employee of theirs who now works at my former employer, who happens to be one of their chief competitors (I know!) This former employee told them that I was fired and that I had overstated my role at my former company, both of which are ridiculously untrue, but I am not surprised as there are only five people who used to work at CallTower and now work at my former company, and most are in Sales. Basically, they had no idea what they were talking about and were in no position to know why I left the company or what my role was there. Had CallTower taken the direct and honest route to obtaining reference information and asked it of me instead of back channelling, I could have put them in touch with several VPs, even the COO or CEO who could have provided them with far better intel on me, but oh well. If a company is going to take the word of a former employee who abandoned ship for a more successful competitor, I don't want to work there anyway. I consider that bullet dodged, so thank you to whoever fed them that bad info on me.