Shopify has taken Rails through some of the world's largest sales: Superbowl, Celebrity Launches, and Black Friday. In this talk, we will go through the evolution of the Shopify infrastructure: from re-architecting and caching in 2012, sharding in 2013, and reducing the blast radius of every point of failure in 2014. To 2016, where we accomplished running our 325,000+ stores out of multiple datacenters. It'll be whirlwind tour of the lessons learned scaling one of the world's largest Rails deployments for half a decade.