Both approaches aim to catch security issues before they cause damage — the real difference is when, and how often.
Security gets reviewed at the end of a development cycle, often as a formal gate before release. This approach does catch issues, but late — at a point where fixes are more expensive to implement and release timelines are already at stake, creating pressure to either delay the release or ship with known issues.
For teams releasing infrequently, with a genuinely dedicated security review step, this can still work reasonably well. The risk grows as release frequency increases and the end-of-cycle bottleneck gets squeezed harder each cycle.
Security checks run continuously, integrated into the same pipeline as testing and deployment. Issues surface while code is still being written and fresh in the developer's mind, when they're both cheaper and faster to fix than after the fact.
This approach requires more upfront investment in tooling and pipeline integration, but pays that investment back over time through fewer expensive, late-stage surprises and a shorter overall path from code written to code safely shipped.
Traditional reviews can work reasonably well for infrequent releases with a genuinely dedicated security gate and enough slack in the timeline to act on findings. Teams shipping frequently benefit more from continuous, automated checks that don't create a bottleneck at every single release.
Team size matters less than people assume — even a small team can integrate meaningful automated checks into an existing pipeline without a dedicated security headcount, starting incrementally rather than trying to build a full DevSecOps practice overnight.
No — even a small team can integrate basic automated checks into CI/CD without a large security headcount, starting with the highest-leverage checks and expanding over time.
Properly implemented, it tends to speed releases up over time by catching issues earlier and avoiding late-cycle bottlenecks, though there's often a short adjustment period while checks get tuned to reduce false positives.