> triple-nine uptime & fault tolerance. Haha, we used to joke that's how many nines our customer-facing Ruby on Rails services had compared against our resilie

> triple-nine uptime & fault tolerance. Haha, we used to joke that's how many nines our customer-facing Ruby on Rails services had compared against our resilient five nines payments systems. Our heavy infra handled billions in daily payment volume and couldn't go down. With the Ruby teams, we often playfully quipped, "which nines are those?" humorously implying the leading digit itself wasn't itself a nine.