Matthew Wilkes refined firewall rules in the DFE-Digital/care-leavers repository to address false positives affecting Snapchat conversion tracking. He excluded the _ScCbts cookie from Azure Front Door managed firewall rules, ensuring legitimate requests were not blocked while maintaining the project’s security posture. Using skills in cloud security, firewall management, and infrastructure as code with HCL, Matthew balanced operational risk by adjusting rule weights rather than removing protections. He documented the rationale for this change and aligned it with estate-wide cookie handling policies, demonstrating a methodical approach to security engineering and contributing to consistent, reliable tracking across the organization’s infrastructure.