Prometheus, a popular tool for collecting and querying real-time metrics, faces scalability challenges in large-scale applications due to its reliance on disk operations for memory management. Thanos addresses these limitations by offering a "highly available Prometheus setup with long-term storage capabilities," allowing data aggregation from multiple Prometheus instances and deduplication of metrics through a single endpoint. Thanos employs object storage, time-based partitioning, and features like the Sidecar component and StoreAPI to manage and store metrics efficiently, even across multiple Kubernetes clusters. Companies like Nubank and GiffGaff have successfully integrated Thanos into their tech stacks, achieving operational efficiency and cost-effectiveness. Thanos enables seamless metric querying and storage, ensuring high availability and minimizing data loss, making it an invaluable tool for organizations seeking to scale their monitoring capabilities.