David Sastre worked on improving vulnerability data quality in the ossf/malicious-packages repository by standardizing NPM vulnerability reporting to comply with the OSV JSON schema. He focused on amending the reporting format to include fixed version information, which enhances the accuracy and completeness of vulnerability records for downstream risk analysis. Using Python, David applied skills in data formatting, NPM package analysis, and schema validation to implement targeted code changes that reinforce data integrity for security teams. His work addressed a specific bug, resulting in more reliable vulnerability data and supporting faster triage and risk assessment for open source security workflows.