Thomas Sarno developed a Document Codes Management Utility for the hmrc/customs-declare-exports-frontend repository, focusing on backend development and configuration management using Scala. He implemented JsonUpdater.scala to centralize the process of adding and deleting document codes, including those requiring justification, and ensured that updates are written back to JSON files in a sorted, deterministic order. This approach improved data integrity and streamlined maintenance by reducing manual editing and audit complexity. The work was aligned with release 4.6.3.1, with traceable commits for release readiness, and positioned the module for easier future expansion of document code rules and configurations.