>The requirement for the code review for internal tools already seems awefully restrictive.
How on earth is that restrictive? Having code review for any important code should be normal at any company. Just because the tool is internal doesn't mean it's trivial and any engineer (especially a 21-year-old: how is she even an employee and not an intern at that age?) should be able to merge anything in willy-nilly.
Why wouldn't she be an employee at 21? 21 is three years into legal adulthood. The idea of being an intern at 21 is degrading. They're adults. Treat them like adults, not children.
Maybe this is news to you, but engineers typically have to go to college and get a degree before they can work as a software engineer. That typically takes 4 years, starting at age 18, which is when most people graduate high school. A 21-year-old working as an "engineer" at a company is typically an intern.
So to answer your inane question, she wouldn't be an employee because she's not old enough to have graduated college yet. And that's just to get a BS degree; lots of engineers these days (esp. at top-tier companies like Google) get an MS degree before they enter the workforce full-time.
I'm rather appalled that I have to spell this out here on this forum.
Getting a degree is largely unnecessary in the present time, and a substantial volume of people skip that step, especially in large companies like Google that are constantly buying others.
How on earth is that restrictive? Having code review for any important code should be normal at any company. Just because the tool is internal doesn't mean it's trivial and any engineer (especially a 21-year-old: how is she even an employee and not an intern at that age?) should be able to merge anything in willy-nilly.