These slides reveal why 51% of web application vulnerabilities trace back to APIs – and walk through the real-world consequences of insufficient testing: expired tokens, changed endpoints, and small bugs that quietly escalate into full-blown data breaches.

This visual guide also makes the case for why validating behavior, performance, and security at every stage isn't optional – it's non-negotiable.

For a full definition and a breakdown of how API testing works, check our glossary article on API testing.