What is OWASP ZAP and where does it fit in a DevSecOps pipeline?

Describe OWASP ZAP by the failure it prevents, not by its feature list. It belongs to DAST (dynamic application security testing) and runs at the test stage of delivery, which matters because the cost of fixing a defect rises sharply the later it is found — the core argument behind shifting security left.

Strong answers cover baseline vs full scans, spidering and AJAX spidering, authenticated scans with session tokens, the API scan for OpenAPI specs, taming scan duration in CI, and interpreting alerts by risk and confidence. Interviewers also listen for the operational side: who owns the rules, how findings reach the developer who introduced them, how false positives get suppressed without silently disabling coverage, and what the break-glass path is when a fix genuinely cannot ship in time.

Tie it to the wider toolchain. Security scanning is only useful when its output is actionable, deduplicated across tools, and attached to a specific commit, image digest or resource — otherwise teams learn to ignore it.