On the Facebook Engineering page you read:
Our development cycle is extremely fast, and we’ve built tools to keep it that way. It’s common to write code and have it running on the live site a few days later. This comes as a pleasant surprise to engineers who have worked at other companies where code takes months or years to see the light of day. If you work for us, you will be able to make an immediate impact.
You see? “A few days later”, “pleasant surprise”, “immediate impact“. They can, you can’t: why?
“It can’t work here! We are different!”.
I see: you are making that difference too.