Tester Interview Questions

What is Fluent Wait in Selenium and when is it used? Compare it with WebDriverWait, explain how to configure polling interval and ignored exceptions, and give a scenario where Fluent Wait is the only viable option.

What is Parallel Testing and why is it useful in automation? Explain how to configure parallel execution in TestNG using the suite XML, the thread-safety concerns with WebDriver instances, and how to manage them with ThreadLocal.

Explain the difference between a Scenario and a Scenario Outline in Cucumber BDD. When would you use a Scenario Outline, and how do you supply multiple data rows using the Examples table? Show a real-world login test example.

What is an Automation Framework? Explain its structure. Describe the layers: test data, page objects, utilities, test runner, reporters. Why is a framework needed vs raw Selenium scripts? Compare Data-Driven, Keyword-Driven, and Hybrid frameworks.

Write Playwright code to handle multiple windows (browser contexts/tabs) and perform actions on a new page. Explain the difference between new page events and popup events, and how to wait for a page load before interacting.

Explain the purpose of the pom.xml file in a Maven project. Describe the key sections: groupId/artifactId/version, dependencies, plugins, build lifecycle phases (compile, test, package, install), and how to add a Selenium + TestNG dependency with the correct scope.

Describe how pop-ups can be handled using Selenium. Cover alert/confirm/prompt dialogs (driver.switchTo().alert()), browser-native file upload dialogs, and custom modal pop-ups built with HTML/CSS.

Describe OOP concepts and how they are applied in automation frameworks. Give concrete examples: Encapsulation in Page Objects (private WebElements), Inheritance for BaseTest/BasePage, Polymorphism for multi-browser driver factories, and Abstraction via interfaces for reporting.

Describe JSON Schema Validation and its importance in API testing. What is a JSON schema? How do you validate that an API response conforms to the expected schema using Rest Assured or Postman? Give an example schema for a user object with required fields and type constraints.

Explain the difference between PUT and PATCH in REST APIs. When is each appropriate? Show how you would test both verbs using Playwright's APIRequestContext, and explain how to validate partial vs full resource updates.

Explain common HTTP status codes returned by APIs (2xx, 3xx, 4xx, 5xx). Differentiate between 401 vs 403, 404 vs 400, and 502 vs 503. How do you validate these in automated API tests?

Describe the role of a Step Definition file in Cucumber BDD. How does Cucumber link a Gherkin step to a Java method using annotations like @Given, @When, @Then? Show a complete example with a feature file and its corresponding step definition.