Recently Google published a paper on their monitoring system Monarch, which happened to have similar design choices to the existing CNCF Incubated project: Thanos! During this talk, two of Thanos maintainers will explain why Thanos could be claimed as an unintentional open source evolution of Google Monitoring Systems like Monarch. Google is known for building massive, global scale solutions. While organizations rarely have a similar scale, we can learn from those solutions while developing in Open Source. We all see the successes of Kubernetes which was inspired by Google Borg, and Prometheus based on Google Borgmon. During this talk, two of Thanos maintainers will explain why Thanos could be claimed as an unintentional open source evolution of Google Monitoring Systems like Monarch. By following this comparison, the audience will learn the general pattern of using and scaling the Thanos system. This talk will also reveal the exciting direction of the project including the map-reduce pushdown for PromQL queries for massive cost reduction (don’t tell anyone!)