Not really anymore, and for a long time: This article is more than 10 years old and describes what impressive tech & metrics they were using already back then:

Not really anymore, and for a long time: This article is more than 10 years old and describes what impressive tech & metrics they were using already back then: https://queue.acm.org/detail.cfm?id=2536492 https://queue.acm.org/detail.cfm?id=2536492