Earlier quoted context omitted.
All attractive places to work but not sure any have higher ratios (except Craigslist perhaps, which has its own peculiarities).
I believe all those companies are above 1M users per engineer, my estimation for FB was just under that. Is my estimate for FB way off?
The most recent estimate I saw was 1.3m users/engineer and steadily climbing. And if we take active users, the gap is even greater. And none of those other companies would enable an engineer's work to get in front of 100s of millons of users.