A phone call and one morning in the office which included several in person interviews with peers, my future manager and a future direct report. It was pretty efficient and pleasant.

Initial telephone screen with hiring manager, follow up telephone screen with a peer, then invited for in person interview with three execs and the owner. After investing pretty significant time for phone interviews, then about four hours in f2f interviews the hiring manager scheduled time with me to follow up on the interviews. Despite having a confirmed meeting time, he completely blew off our planned call with no notice, explanation , follow up, let alone an apology for missing our appointment. Despite two attempts to follow up with him, not even the courtesy of a return call or a brief email (or text). Complete waste of time, major red flags.