Not a meritocracy

I have been working at Amazon for more than 3 years. There are a lot of good things about working for Amazon, but the bad parts make it definitely not worth it.

The worst part is that everything is very political in regards to promotions. The criteria to progress within the company has a lot of grey area and this widely abused by managers everywhere. 

The "superstars" selected by managers as their favorites are promoted very quickly. On the other hand, the folks who do their job well but aren't as favored as the "superstars" are left to essentially figure out they've hit a ceiling when they are being pressured to transfer to another team or leave the company.

Despite what Amazon says, the reason for such high turnover in the company is not the work life balance and that many people aren't willing to work hard. There are a few of those, but most turnover is because the competition is fierce for promotions and the politics wins out instead of real performance in nearly every case I've seen. Amazon is not a meritocracy, so don't believe it for a minute.