We've all been there—a test fails randomly, passes locally but fails in CI, and leaves no clear trace of what went wrong. This talk will explore advanced debugging techniques to identify and fix these elusive test failures. We’ll look at how to use browser logs, network captures, and test execution traces to uncover the true cause of test flakiness. I'll share real-world debugging scenarios from Selenium tests and how to apply structured root cause analysis to stabilize your test suite.