Secure by Design is a software development philosophy that treats security as a foundational requirement rather than an afterthought. Instead of building a product first and bolting on security fixes later, Secure by Design demands that security considerations are embedded into every stage of the development lifecycle — from architecture and design through coding, testing, deployment, and maintenance. The core idea is straightforward: If you build something securely from the ground up, your users are protected by default rather than only when they know how to flip the right settings or when security gaps are fixed after the fact. In practical terms, this means adopting several core security principles: - Least privilege ensures that processes, agents — AI or otherwise — containers, and system services receive only the minimum access they need. - Secure defaults make sure products ship with the safest configuration enabled out of the box. - Defense in depth layers multiple security controls so no single failure becomes catastrophic. And organizations can further strengthen resilience by eliminating entire classes of vulnerabilities through safer languages, frameworks, and design patterns. Why was the Secure by Design approach introduced? For decades, many players in the technology industry operated under a “ship fast, patch later” model. One consequence of that legacy is that cybersecurity can be seen as just a cost center — something that slows releases and frustrates developers. The impacts are playing out in real time: constant vulnerability disclosures, rushed emergency patches, and breaches that drain billions from organizations while exposing the personal data of hundreds of millions of people. The Ivanti Connect Secure vulnerabilities, the Log4Shell exploit in a ubiquitous open-source library, and the MOVEit Transfer vulnerabilities all demonstrated that reactive security simply cannot keep pace with determined adversaries. Recognizing this imbalance, the U.S. Cybersecurity and Infrastructure Security