> 10 days paid time off is the de-facto standard for just about every company based in this country.

Not to mention that tech industry firms are reputed to be more generous than what is otherwise common, that sounds really low even outside of the tech industry; its lower than any company I've seen, and lower than what most sources I've seen indicate is common. [0]

[0] e.g., http://www.bls.gov/news.release/ebs.t05.htm and http://www.salary.com/time-off-paid-time-off-from-work/

What's probably happening here is there are company-selected vacation days being left out of the number. You get to choose 10, but another 10 are picked by the company.

I worked as a programmer at a big boring company which did this - 10 days of company holidays, 10 days of you-get-to-choose. It's a month off total, but you only have control over 2 weeks, so it's presented as 10 vacation days.

> What's probably happening here is there are company-selected vacation days being left out of the number.

The first source I linked provides actual averages for paid holidays, paid vacation, and paid sick leave.

10 paid vacation days is dead average for professional, technical, and related employees -- with only one year of service, and low for such employees with more service.

Much less standard for SV engineers. I don't know of any tech company with 10.

Everywhere I've worked has had "unlimited" vacation policies. I've actually taken about 4 weeks per year.

Not in my experience for what it's worth. Every software dev position I've held in the last 10 or so years offered 4 weeks.