Before incorporating the DevSecOps process, when was security applied in the software- development lifecycle?

Applying security in every step is the principle of DevSecOps, not the traditional approach.

Security was not typically integrated right in the middle; it was largely a final, separate phase.

Historically, security was often treated as an afterthought in traditional software development, primarily applied right at the end of the lifecycle after development was completed. This 'bolt-on' approach led to late detection of vulnerabilities and costly rework.

Applying security right at the beginning is a 'shift-left' approach, characteristic of modern secure development, not the pre-DevSecOps norm.