Alex Snowden developed secure Vault AWS IAM login header support for the DataDog/datadog-agent repository, focusing on enhancing authentication by integrating the X-Vault-AWS-IAM-Server-ID header. Working in Go, Alex updated the VaultSessionBackendConfig and authentication flow to validate this header, reducing replay attack risks and aligning with enterprise Vault requirements. The implementation included comprehensive unit testing and manual integration tests against a development Vault instance to ensure compatibility with existing secret management. By reinforcing the authentication pipeline and preparing for migration to native Vault login, Alex demonstrated depth in backend development, API integration, and test-driven engineering within a complex infrastructure environment.