"10% annual turnover" without knowing the size of the company is meaningless. If there's 3000 employees that's a pretty bad sign. If there's 5 employees, that's actually worse because someone has been cut in half.

I'd also prefer a team/department size. I don't really care if all the sales staff are happy, I do care if the developers have high turnover.

As someone whose first startup failed due to a complete lack of sales, I don't agree. It's easy to dismiss any particular business function you're not interested in, but entirely wrong too. Everyone has a role to play - even the happyiedt engineering team won't keep a business going if you're building something that needs people to sell the product.

I highly doubt it. If he had said "10% annual turnover for all people" that would be a really decent signal. He had to add in "that passed probation" so it is probably a horrific culture. Just putting that disclaimer raises huge red flags

I agree. Did they get rid of a lot of people on probation? They're standards may not be realistic and joining would be a big risk. Are a lot of people quitting before the base probation? That's a pretty big indication to run.

Maybe that's just their approach to hiring? Everybody says it's broken and hard and whatnot. Maybe they just don't bother much with programming puzzles and "What's your biggest weakness?" questions. If both sides are aware of this approach from the start, it could be fine, no?

Or maybe I just lack empathy for this situation because I have never been fired.

If both sides are aware, sure. I suspect that they would begin hiding this information though as it would prevent a lot of potential hires from people already in stable jobs.

That is a really nasty process for the people they hire though. It would not be fine.