Denis Ko developed the Croissant Metadata Saving feature for Hugging Face Datasets in the ServiceNow/Fast-LLM repository. He automated the process of retrieving dataset metadata from the Hugging Face Hub API or copying it from a local directory, then writing it as a croissant.json file to the output directory. Using Python, Denis focused on API integration, data preparation, and file handling to streamline structured metadata generation. This work improved dataset preparation by ensuring metadata-driven reproducibility and readiness for downstream machine learning workflows. The feature was delivered without major bugs, reflecting a focused and well-executed engineering effort within a one-month period.