Mark Leith developed Zerotrust Packet Routing (ZPR) security enhancements for the HeatWave service in the oracle/terraform-provider-oci repository. He focused on strengthening the security posture of MySQL DB systems and replicas by introducing new security attributes and updating Terraform configurations using Go and HCL. Mark expanded integration tests to ensure correct ZPR behavior and reliable security attribute propagation, emphasizing end-to-end validation for OCI deployments. He also refreshed documentation to guide users on the new security features. The work demonstrated depth in cloud infrastructure and security, addressing both implementation and validation to improve reliability and maintainability for Oracle Cloud deployments.