During January 2026, Mohamed Sadok Khouaja focused on backend stability for the prebid-server repository by addressing a critical input validation issue. He implemented a targeted bug fix that enforced publisher path values to conform to a predefined enum list, thereby strengthening data integrity and improving request routing reliability. Using Go and leveraging JSON schema validation, Mohamed ensured that only valid publisher path inputs could proceed through the ad request processing stack. This work enhanced the robustness of the API layer and prevented invalid data from entering downstream systems. The contribution demonstrated careful attention to backend correctness and input validation best practices.