Had an experience like this recently with a certain media streaming hardware company that starts with an "R". Their process had six points of contact, starting with an initial technical phone screen (with a language feature quiz), an hour long algorithm session (actually surprisingly fair), and then four more 45 minute interviews after that. They'd made a point of saying how good they were at getting back to people in 24 hours, and then they ghosted me. As far as I could tell, it was going alright, too.