How Yahoo Calendar broke free from hardware queues and DBA bottlenecks

Editor's note: Yahoo Mail is in the midst of one of its largest infrastructure transformations to date: a multi-year effort to modernize hundreds of petabytes of services by moving to Google Cloud.The Yahoo Mail migration - a high-scale always-on workload - began with Yahoo Calendar, a product that is an essential part of the experience for hundreds of millions of Yahoo Mail users.  It was a massive undertaking with no room for error, and the result was a smooth cutover with no customer impact that proved Cloud SQL could handle the complexity and pace of Yahoo’s operations. It also marked a shift in how Yahoo works by reducing manual overhead, unlocking developer agility, and laying the foundation for what comes next.

At Yahoo, we knew migrating our cornerstone platform — Yahoo Mail — to the cloud would be one of the most significant infrastructure efforts we’d ever taken on. With ...