Great chat with HR, chap was extremely personable, really sold the role, and I exceeded all of the requirements on the JD.
Met with CTO a few days later who was the most rude and dismissive person I've ever met in my professional career. Apparently she was looking for someone with several years experience in the role already (this wasn't on the JD, and I was looking to move up in my career). She said "my time is important and I don't want to waste it talking to someone not qualified". Didn't even bother asking any questions to see if I had the experience if not the role.
This was either a bizarre hazing ritual to see how I'd handle the challenge of being spoken down to, or shows a lazy person who couldn't be bothered to spend 30 seconds glancing at a resume before the interview was booked. In either scenario, not a person I'd want to work for. The role is still open several months later so I'm assuming no-one else wants to either.