Worked on enhancing GuardDuty resource lifecycle management for multi-account environments in both the hashicorp/terraform-provider-aws and opentofu/terraform-provider-aws repositories. Focused on automating cleanup of GuardDuty-managed resources during VPC and subnet destruction, the work introduced structured tflog logging, refactored common utilities, and improved ownership semantics for shared VPCs. Leveraged Go, AWS SDK, and Terraform to move cleanup logic out of retry loops, expand test coverage, and address memory management by shifting to stack allocation. These changes reduced deletion blockers, improved cross-account governance, and increased maintainability, while also clarifying documentation and standardizing logging practices across the codebase.