Automation Testing Interview Questions in Noida

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Check whether the element is inside an iframe or shadow DOM, the locator matches a different hidden element first, the page opened in a new tab not yet switched to, or the wait condition is wrong, such as presence versus visibility versus clickable. Use findElements to see how many matches the locator has and verify it in browser DevTools.

How do you test an API that depends on another service that is down?

API Testing and CI/CDMedium

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Use mocks or stubs such as WireMock to simulate the dependency and test your service in isolation.

Why do Selenium browser containers need a larger shm_size?

Selenium Grid & DockerMedium

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Chrome and Firefox use shared memory at /dev/shm for rendering and inter-process communication. Docker gives containers only 64 MB of shared memory by default, which is not enough for modern pages, so the browser tab crashes with errors like session deleted because of page crash. Setting shm_size to 2g in Compose, or --shm-size=2g with docker run, fixes it. Mounting /dev/shm from the host is an alternative.

List common TestNG annotations and their order.

TestNG FrameworkEasy

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BeforeSuite, BeforeTest, BeforeClass, BeforeMethod, Test, AfterMethod, AfterClass, AfterTest and AfterSuite.

What metrics do you track for test automation in CI/CD?

API Testing and CI/CDHard

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Useful metrics are pass rate per run, flaky test rate, average and slowest test duration, pipeline time to feedback, defects caught by automation versus escaped to production, automation coverage of critical flows and time spent on maintenance. Trend them over weeks. Metrics should drive action, such as fixing the top flaky tests, not just fill dashboards.

Difference between absolute and relative XPath?

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Absolute starts from the root (/html/...) and breaks easily; relative starts anywhere with // and is more stable, for example //input[@id='email'].

What is method chaining in Page Object Model?

Page Object ModelMedium

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Method chaining means page methods return a page object, either this or the next page, so calls can be linked: loginPage.enterUser("asha").enterPassword("x").submit().openOrders(). Returning the next page models navigation and makes tests read like a user journey. Be careful when an action can lead to different pages; return the correct type or provide separate methods for success and failure.

What is polymorphism and how does it show up in Selenium?

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One interface, many forms. WebDriver driver = new ChromeDriver() lets the same test code run on any browser class that implements WebDriver.

How do you avoid page object classes becoming too large?

Page Object ModelMedium

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Split pages into components for repeated or complex areas, keep only user actions as public methods, move generic helpers to BasePage or utilities, and avoid one method per element. If a page has distinct modes like view and edit, use separate classes. Review page classes during code review and refactor when they cross a few hundred lines.

Your Selenium tests in CI produce blank screenshots in headless mode. What could be wrong?

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The screenshot may be taken before the page renders, the window size in headless mode may be tiny, or the browser is crashing due to low shared memory in Docker. Set --window-size=1920,1080, use the new headless mode, wait for page content before capturing, and add --disable-dev-shm-usage or a larger shm size for containers.

What is a webhook and how do you test it?

API Testing and CI/CDMedium

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A callback where one system sends an HTTP request to another when an event occurs. Test with a mock receiver or tools such as webhook.site and verify the payload.

What is the difference between a Docker image and a container?

Selenium Grid & DockerEasy

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An image is a read-only template that contains an operating system layer, software and configuration, for example selenium/standalone-chrome with Chrome and ChromeDriver installed. A container is a running instance of an image with its own process, network and writable layer. You can start many containers from one image and destroy them after a test run. This is why every run starts from the same clean browser environment.

How have you handled disagreement with a developer about whether something is a bug?

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Situation: a developer said a rounding difference in invoice totals was expected. Task: resolve it without friction. Action: I checked the requirement, found it specified rounding per line, and brought the document and a test case with expected values to a quick call with the BA. Result: the BA confirmed it was a bug, it was fixed, and we added the rule to the acceptance criteria.

How do you integrate Selenium tests with Jenkins?

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Create a job or pipeline that checks out code, runs mvn test, publishes reports and triggers on commits or schedules.

Tell me about a time you worked with a team in a different location or time zone on automation.

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Situation: our developers were in another time zone and test failures waited a day for replies. Task: reduce delays. Action: I wrote clear failure reports with screenshots, logs and steps, recorded short videos for complex issues, and set a fixed 30-minute overlap call twice a week. Result: turnaround on defects dropped from two days to about one, and fewer issues bounced back.

A test reading a properties file works in the IDE but fails in Jenkins with FileNotFoundException. Why?

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The file path is probably hard-coded or relative to the IDE working directory, or uses Windows backslashes while Jenkins runs on Linux. Load the file from the classpath with getClass().getClassLoader().getResourceAsStream("config.properties") and keep it in src/test/resources, or build paths with Paths.get. Also check the file is committed to Git and not ignored.

How do you handle stakeholders who ask for performance testing only a few days before go-live?

Performance Testing with JMeterMedium

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Situation: a product team requested load testing three days before launch. Task: give useful results fast and set expectations. Action: I explained the risk, agreed on the two most critical journeys, reused API scripts and ran a short load and spike test, sharing results daily. I also proposed adding a performance stage to future sprints. Result: we found a missing database index before launch, and the next release included performance tests from the start.

During a load test response times rise sharply. Which server-side metrics do you check?

Performance Testing with JMeterMedium

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Check CPU and memory usage of application servers, garbage collection pauses and heap usage for Java services, thread pool and connection pool saturation, database slow queries, locks and connection counts, disk I/O and network bandwidth. Also look at load balancer and cache hit rates and error logs. Correlate the timestamp of the slowdown with these graphs in an APM or monitoring tool to find which resource saturated first.

Describe a time you received critical feedback on your test code.

Core Java for TestersEasy

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Situation: in my first code review, a senior said my tests were hard to read and used Thread.sleep everywhere. Task: improve without getting defensive. Action: I asked for examples, replaced sleeps with explicit waits, extracted helpers and followed the team's naming conventions. Result: my next pull requests were approved faster, and I later used the same checklist to review a junior's code.

How do you read data from Excel or properties files in Java?

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Use Apache POI for Excel and the Properties class for config files, loaded in a utility class so tests read data instead of hard-coding it.

What is the difference between a declarative and a scripted Jenkins pipeline?

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Declarative pipelines use a fixed structure: pipeline, agent, stages, steps, post, with built-in options and validation; they are easier to read and are the recommended default. Scripted pipelines use node blocks and full Groovy, giving more flexibility for complex logic but making them harder to maintain. Most test pipelines use declarative syntax with small script blocks only where needed.

Your pipeline runs the full test suite on every commit, even for documentation-only changes. How do you optimise it?

API Testing and CI/CDHard

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Use path filters so commits that touch only docs or markdown skip the test stages. For code changes, map modules to their test suites and run only the affected ones on pull requests, with the full regression on merge to main or nightly. Cache Maven dependencies and Docker layers. Keep a fast smoke stage first so failures appear early. Track pipeline time as a metric so the optimisation does not quietly regress.

What is the purpose of testng.xml?

TestNG FrameworkEasy

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A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.

How do you handle authentication types in REST Assured?

REST AssuredMedium

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Basic auth uses auth().preemptive().basic(user, pass). Bearer tokens are set as a header: header("Authorization", "Bearer " + token). OAuth 2.0 can use auth().oauth2(token) after fetching the token from the token endpoint. API keys go in a header or query param. Fetch tokens once per suite or cache them with an expiry check rather than logging in before every test.

What is shift-left testing?

API Testing and CI/CDEasy

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Shift-left means testing earlier in the development cycle: reviewing requirements, writing acceptance criteria and test cases before coding, running unit and API tests on every commit, and giving developers fast feedback. Defects found early are cheaper to fix. In practice SDETs pair with developers, add tests to pull request pipelines and test APIs before the UI is built.

What is RemoteWebDriver and how is it different from ChromeDriver?

Selenium Grid & DockerEasy

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ChromeDriver starts and controls a browser on the same machine as the test. RemoteWebDriver sends the same WebDriver commands over HTTP to a remote endpoint, such as a Selenium Grid, a Docker container or a cloud provider, which starts the browser elsewhere. You pass the Grid URL and browser options, and the rest of the test code stays the same. ChromeDriver itself actually extends RemoteWebDriver.

What are Maven profiles and how do you use them in automation?

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Profiles are sets of configuration activated by name, such as -Pqa or -Pstaging, or by conditions. In automation they switch environment URLs, suite files, browsers or parallel settings without changing code. For example a regression profile sets suiteXml to regression.xml and threadCount to 4. Combined with properties files, profiles keep one codebase for every environment.

How do you verify that an element is displayed, enabled or selected?

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Use isDisplayed(), isEnabled() and isSelected() on the WebElement before interacting or asserting.

How do you group tests?

TestNG FrameworkMedium

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Tag tests with groups = {"smoke","regression"} and include or exclude them in testng.xml to run chosen sets.

A developer changed the UI and 40 tests failed with NoSuchElementException. How does POM help here?

Page Object ModelMedium

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Because locators live only in page classes, I check which page object methods fail, update the changed locators in those few classes, and rerun. Usually 40 failures map to two or three locators. I would also ask developers to add stable data-testid attributes and review UI changes with QA early, so future changes do not break tests unexpectedly.

What is the Background keyword and when should you avoid it?

Cucumber and BDDMedium

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Background holds steps that run before every scenario in a feature file, such as opening the app and logging in. It removes repetition in Given steps. Avoid it when it becomes long, when only some scenarios need it, or when it hides important context, because readers then cannot understand a scenario on its own. In that case use a hook or a clearer Given step.

How do you test API security basics as an automation tester?

API Testing and CI/CDHard

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Check that endpoints reject missing or invalid tokens with 401, block users from other users' data with 403 or 404, validate input to prevent injection, do not leak stack traces or sensitive fields, enforce HTTPS and set security headers. Automate these as negative tests in the regression suite and work with the security team for deeper penetration testing.

How do you store passwords and tokens safely in Jenkins?

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Use the Jenkins Credentials store and bind them in the pipeline with withCredentials or the credentials() helper in environment blocks. Jenkins masks the values in console logs. Never hard-code secrets in the Jenkinsfile, pom.xml or properties files committed to Git. For larger setups, integrate a vault service and give each job only the credentials it needs.

How do you build dynamic JSON request bodies without hard-coded strings?

REST AssuredMedium

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Use POJOs with a builder pattern or Lombok @Builder, so tests write User.builder().name("Ravi").role("QA").build(). For quick cases use a HashMap or Jackson ObjectNode. For large templates, keep a JSON file and change fields with a JSON library. Combine with a faker library for unique values. This avoids escaping issues and makes changes to the schema easy to update.

What are Cucumber Expressions and how do they differ from regular expressions?

Cucumber and BDDMedium

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Cucumber Expressions are the default, simpler way to match steps, using parameter types like {int}, {string}, {word} and {float}. For example "I add {int} items" captures a number and converts it to an Integer automatically. Regular expressions are still supported and offer more control, but are harder to read. Teams usually prefer Cucumber Expressions and define custom parameter types for domain values.

How do you handle dropdowns in Selenium?