Langfuse and Braintrust offer solutions for LLM observability and tracing but cater to different needs and approaches. Langfuse is an open-source platform focused on tracing and monitoring, allowing teams to create custom workflows by providing core observability primitives, making it ideal for teams with DevOps resources who want to build their own evaluation and CI/CD infrastructure. In contrast, Braintrust is an end-to-end AI development platform that seamlessly integrates observability with systematic improvement, turning production traces into evaluation cases with a single click, and providing CI/CD integration with live evaluation results displayed on every pull request. It facilitates a unified workflow for product managers and engineers, enabling rapid iteration without handoffs, making it suitable for teams needing systematic quality improvement and rapid deployment. While Langfuse requires more custom engineering to connect observability to improvement, Braintrust includes these capabilities out-of-the-box, which is reflected in its pricing and deployment options. Both platforms have distinct advantages depending on the team's resources, deployment needs, and whether they prioritize open-source transparency or integrated workflows for shipping AI products.