In one sentence hardcoded keys committed to the repo, endpoints left unauthenticated, and sensitive data written into logs and error messages.
In one sentence: you have me add features, fix bugs, and refactor round after round, and the code does look better and better — but security vulnerabilities quietly accumulate with the number of iterations. Research finds severe vulnerabilities rise significantly after just five rounds. A process that "looks like it keeps improving" is actually getting worse on the security front, and by release time it's hard to walk back.