Langfuse, an open-source LLM engineering platform, initially launched with a simple Postgres-based architecture that allowed rapid deployment and proved popular with enterprises needing data observability without external data transfers. However, as demand grew and more companies integrated Langfuse, the platform faced scalability challenges with billions of rows and complex queries. To address these issues, Langfuse re-architected its system around ClickHouse, a columnar OLAP database, which offered better performance and scalability. This transition was carefully communicated to their self-hosted user community through open discussions and guided migrations, resulting in a successful rollout. Langfuse now provides a range of deployment options, including Docker Compose, Helm charts, and ClickHouse Cloud, catering to both small-scale setups and large enterprises. This strategic shift has allowed Langfuse to maintain ease of adoption while supporting enterprise-scale workloads, positioning it for future growth.