In July 2025, Jussi Kuusipalo developed the System Prompt Feature for the chat script in the ml-explore/mlx-lm repository, enabling users to specify guiding prompts for chat models to improve the evaluation of fine-tuned models. He implemented this feature using Python, focusing on back end development and robust unit testing to ensure reliability. The work included automated tests that validated the integration and functionality of the new system prompt, supporting more consistent experiment results and streamlined evaluation workflows. All changes were tracked through Git for clear traceability, reflecting a methodical approach to feature delivery and test-driven development practices.