> There could also be technical issues preventing Google from open sourcing its implementation, although I don't know any. My understanding is that sharing det

> There could also be technical issues preventing Google from open sourcing its implementation, although I don't know any. My understanding is that sharing details takes time off very valuable employees, away from fixing important internal issues – a lot more than the company being afraid those details might leak. For the handful of companies who can and needs to implement equivalent, poaching said employees is simpler than back-engineering from blogposts and it makes implementation easier.