Google is enhancing software security by integrating AI agents directly into its development process. This proactive approach aims to prevent vulnerabilities as code is written, rather than detecting them later. The system uses pervasive pre-submit scanning, evaluating every code change in real-time before it's committed. This contrasts with traditional, slower, one-off scans that often identify issues too late. To improve accuracy, they utilize localized threat models that leverage live codebase metadata and dependency information. Specialized triage agents then perform rapid, lightweight validation to confirm potential vulnerabilities. This two-step process ensures low latency without compromising precision. Automated bug-fix agents autonomously generate code patches based on scan results. These fixes are then submitted for human review, significantly shortening the detection-to-resolution cycle. This AI-native strategy has prevented hundreds of vulnerabilities monthly from entering Google's codebase. Organizations can adopt similar principles, separating systems, using context wisely, building robust harnesses, and automating fixes.