Sentry recently introduced Snuba, its new primary storage and query service for event data, backed by open source column-oriented database ClickHouse. To transition from its existing storage systems to Snuba, Sentry followed a complex process that involved testing and validation, including the use of an intermediary called the Service Delegator. The Service Delegator allowed Sentry to execute queries against both the old and new backends concurrently, enabling the collection of data on similarity between the two systems. This data was used to monitor performance and identify areas for improvement, ultimately leading to a successful launch with minimal user impact. By running Snuba in production for months before launching it to end-users, Sentry gained operational experience and confidence in the new system, making the launch day practically uneventful.