Mixpanel has introduced Query-Time Sampling as a solution to the challenges posed by their previous method of ingestion-time behavioral sampling, which was used to achieve fast and cost-effective analytics at scale. While ingestion-time sampling helped maintain rapid analytics by sampling data at the user level, it led to significant drawbacks such as data loss, trust erosion, reduced messaging reach, weakened A/B test significance, and irreversible data loss. In contrast, Query-Time Sampling retains all data and allows users to toggle sampling on or off during query execution, providing both speed and accuracy without data compromise. This new approach is supported by Mixpanel's core infrastructure enhancements, including a database migration to Google Cloud and a decoupling of storage from compute resources, aligning with their user-centric pricing model to support scalable analytics. Query-Time Sampling will soon be available for eligible Enterprise customers, offering a significant advancement in data analytics capabilities.