Over three months, Jaro contributed to the sodadata/soda-core repository by building features and fixing bugs that improved data quality and SQL generation. He developed null-aware validation metrics, enabling accurate inclusion of NULL values in valid and invalid counts by conditionally modifying SQL queries in Python. Jaro enhanced the SodaCL parser using ANTLR and Jinja templating, allowing flexible variable substitution and support for numeric-prefixed identifiers, which improved parsing robustness. He also resolved a Dask-related bug in row count queries, adding targeted tests to ensure reliability. His work demonstrated depth in parser development, configuration management, and distributed data engineering.