Fairly informal, chats with senior managers and directors. Old boys club, one person a director knew in the industry didn't like me (although I'm pretty sure it's a guy who has never met me) so they ignored my references and pulled the offer at the end of the process after they'd informally agreed I was clearly the best candidate for the role in terms of skill and experience. Doesn't matter in hindsight now as they're an obsolete dead company and the director who interviewed me moved on a few months later.