I was invited for a first interview, then a second to do a presentation. Then the hiring manager could not make up his mind so they dragged me back in for a third. They used lots of big words that had very little meaning and even after 3 gruelling interviews I still did not understand what on earth they actually did. Their website was no help either. Eventually got a 4th informal interview for a different role. More big words. Finally on my first day some explained to me what their product was. The website has since be revamped.