Secure Software Development Lifecycle (SSDLC)

An SSDLC formalizes when and how security work happens during software delivery rather than treating it as a one-off audit. Typical phases include security requirements, threat modeling, secure architecture review, secure coding standards, code review, SAST, SCA, DAST/IAST, penetration testing, release gates and runtime monitoring. Frameworks such as Microsoft SDL, OWASP SAMM and NIST SSDF describe the practices and maturity levels to aim for. The benefit is predictable risk reduction: vulnerabilities are caught and fixed when they are still cheap, and compliance evidence is generated as a by-product of normal engineering work.