The founders of Dash0, a company that provides an OpenTelemetry-native observability platform, have chosen ClickHouse as their primary storage solution. This decision was influenced by their experience with Instana, another company they founded, and their need for greater efficiency and scalability in handling large volumes of telemetry data. ClickHouse's columnar architecture, compression capabilities, and flexible schema design make it an ideal choice for storing high-cardinality telemetry data. The team has optimized ClickHouse's operational aspects to balance maintainability, performance, and cost efficiency. They have also implemented a hybrid storage approach combining AWS S3 storage with temporary local storage to manage large customer accounts and reduce storage costs. The ClickHouse database is used as the main storage for all OpenTelemetry data, with PostgreSQL handling customer-specific settings and related data. The team has carefully designed table schemas, including primary keys, aggregation strategies, and indexing techniques, to achieve both speed and storage efficiency. They have also implemented sampling strategies to improve query performance and have optimized JOINs to reduce memory consumption. Overall, the implementation of ClickHouse as the foundational storage layer for Dash0 demonstrates the power of a thoughtful database architecture in supporting high data volume and cardinality while maintaining performance at scale.