During February 2026, McGrew contributed to the openai/codex repository by enhancing observability and policy governance in backend systems. They implemented a feature that adds the host.name resource attribute to OpenTelemetry logs and traces, using Rust to resolve hostnames via gethostname and verifying correctness through comprehensive unit tests. Additionally, McGrew embedded OpenTelemetry-based policy audit logging within the codex-network-proxy, enabling structured tracking of network policy decisions for improved compliance visibility. Their work demonstrated depth in backend development, network programming, and audit trail implementation, resulting in more robust troubleshooting capabilities and clearer audit trails without introducing new bugs during the development period.