Flash Sale Engineering

From stores with ads in the Super Bowl to selling Kanye’s latest album, Shopify has built a name for itself handling some of the world’s largest flash sales. These high profile events generate write-heavy traffic that can be four times our platform’s baseline throughput and don’t lend themselves to off-the-shelf solutions.

This talk is the story of how we engineered our platform to survive large bursts of traffic. Since it’s not financially sound for Shopify to have the required capacity always running, we built queueing and page caching layers into our Nginx load balancers with Lua. To guarantee these solutions worked, we tested them with a purpose-built load testing service.

Although flash sales are unique to commerce platforms, the lessons we learn from them are applicable to any services that experience bursts of traffic.

Emil is a production engineer at Shopify where he works on performance, the production pipeline, and DNS tooling. When he's not trying to make Shopify's global performance heat map green, he's shivering over a spiked cup of coffee in the great Canadian north.