ClickHouse is an open-source columnar database company purpose-built for real-time analytics at massive scale. Originally created at Yandex, it spun out as an independent company in 2021. The core commercial product — ClickHouse Cloud — is a fully managed cloud database that lets enterprises run SQL queries across billions of rows in milliseconds. Primary use cases: product analytics, observability (logs/traces/metrics), security telemetry, financial analytics, and AI/ML workloads. The company recently expanded beyond analytics by acquiring Langfuse (LLM observability for AI teams) and launching a native Postgres service (transactional workloads), building toward a unified data + AI stack. Buyers are data engineering, platform, and analytics teams at both high-growth tech companies and large enterprises. Notable customers include Meta, OpenAI, Anthropic, Tesla, Capital One, and Sony. ClickHouse competes on query speed, cost efficiency, and open-source community scale against cloud data warehouses and observability vendors alike.