The Art of Rejection: Mastering Failure Scenarios for API Security Validation at Runtime

How an API handles invalid requests tells you a great deal about its security posture. Verbose error messages, inconsistent rejection behaviour, and improper HTTP status code usage all create signals that attackers can exploit — and that monitoring can detect.

This video covers what well-designed API rejection looks like, why testing failure scenarios is essential for security validation at runtime, and how active monitoring of error behaviour contributes to a stronger overall API security posture.