TestNG Framework — Complete Course
Full TestNG reference — annotations and execution order, testng.xml suites/tests/parameters, DataProviders, groups and dependencies (skip vs fail), parallel execution and thread safety, hard vs soft assertions, listeners, a custom retry analyzer, Selenium integration, best practices, and 50 interview cross-questions.
TestNG is one of those frameworks everyone uses but half-understands — most people know @Test and @BeforeMethod and stop there. The parts worth your time here are execution order, DataProviders, and the custom retry analyzer, because those are what actually separate a flaky suite from a reliable one. The 50 cross-questions at the end are genuinely interview-style, not generic — I'd work through those before the reference chapters if you're short on time.