Awful. After a series of IQ/behavioral tests, you can expect a series of video/in-person interviews with "senior management".
One exec actually said during the interview, complaining about a current employee, "Everything is ok, but if you don't get things done, then we are going to have words." He also was quite forthright about having a bad temper.
Another senior staffer -- whose seemingly only qualification for being an exec is that he's been there a while, but with no previous skill set, pushed for answers to questions that were not applicable to the role. When I tried to explain how I would solve the problem, he came back and literally insisted I "pick a color".
The CEO seems to have control/trust issues and likes to play power games.
Beyond these red flags, they have little respect for candidates and employees. Asking you to make yourself available for in-person interviews with less than a days notice. They expected me to drop everything (including other work obligations), to make myself available for them.
And finally, they repeatedly spoke poorly about the staff they already had. Briefly observing what I did, I saw overworked people that were desperate for work, otherwise they would have been long gone.