Boundary's BAML programming language aims to bring engineering discipline and type safety to LLM workflows by defining prompts as typed functions with clear inputs, outputs, and schemas. This allows developers to test, version, and debug prompts like any other code, enabling a hot reload loop for LLMs and reliable extraction of structured data from model output. By integrating BAML with ClickHouse, the Boundary team provides a complete analytics backbone for prompt engineering, offering schema-aware logging, real-time observability, and fast query capabilities to transform the way developers build and maintain LLM applications.