Grafana Labs has transitioned from contributing to the Cortex project, a horizontally scalable Prometheus implementation for global metric views and long-term storage, to launching Grafana Mimir. Both Cortex and Thanos, a newer project, aim to solve similar challenges but through different methodologies; Cortex uses a centralized push-based model, while Thanos operates with a fanout query system leveraging existing Prometheus servers. Both provide solutions for global metric visibility, high availability, and long-term storage, with Thanos using object stores and Cortex utilizing a combination of object and NoSQL stores, which impacts cost and performance trade-offs. The projects, both built on the Prometheus codebase and part of the CNCF sandbox, have begun collaborating, with efforts like integrating Cortex's query frontend for Thanos and allowing Cortex to adopt Thanos' storage approach, promising improved scalability and cost efficiency as they continue to evolve.