Automation Testing Interview Questions for E-commerce &amp; consumer tech Companies

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Arrays have a fixed size and can hold primitives; ArrayList grows dynamically, holds objects and offers helper methods.

How do you handle a dropdown that is not a <select> tag?

Selenium WebDriverMedium

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Click to open the dropdown, then locate the option by its text, e.g. //li[text()='India'], and click it. Add an explicit wait for the animation.

Mobile tests pass on the emulator but fail on a low-end real device. How do you investigate?

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Low-end devices are slower, so fixed waits and short timeouts expire before screens render. Replace sleeps with explicit waits and increase timeouts sensibly. Check for vendor-specific pop-ups, battery optimisation dialogs or different keyboards on that brand. Compare screen size and resolution, since coordinate-based taps break. Collect device logs with adb logcat and screen recordings to see what the app was doing. Also check whether the app crashed due to low memory.

How do you test deep links in a mobile app with Appium?

Appium Mobile AutomationHard

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On Android use the mobile: deepLink command with the URL and package, for example driver.executeScript("mobile: deepLink", Map.of("url", "shop://product/42", "package", "com.example.shop")). On iOS simulators driver.get with the custom URL opens it, though Safari may show a confirm dialog to handle. Then assert that the correct screen and data are shown. Deep links are also a great shortcut to reach deep screens quickly in other tests.

Your price comparison test fails because 19.99 + 0.01 is not equal to 20.0. Why?

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double uses binary floating point, which cannot represent many decimal values exactly, so small rounding errors appear. For money, use BigDecimal created from strings and compare with compareTo(), or compare doubles with a tolerance such as Assert.assertEquals(actual, expected, 0.001). Also strip currency symbols and commas before parsing UI text.

Tell me about a time you moved from web automation to mobile automation.

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Situation: my team needed Android regression tests and I only knew Selenium. Task: deliver a smoke suite in one month. Action: I learned Appium 2 setup, used Appium Inspector to find locators, asked developers to add accessibility ids, and reused our TestNG, POM and reporting structure with a new driver factory. Result: twenty smoke tests ran nightly on emulators within four weeks, and release smoke testing dropped from half a day to forty minutes.

What is the Optional class in Java and where is it useful in test code?

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Optional is a container that may or may not hold a value, introduced in Java 8 to avoid returning null. In test code it suits lookups that can legitimately find nothing, such as finding a row in a table or reading an optional config key. Callers use orElse, orElseThrow or ifPresent instead of null checks. For example, findRowByName(name).orElseThrow(() -> new AssertionError(name + " not found")) gives a clear failure message.

What is the difference between SOAP and REST?

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SOAP is a strict XML protocol with WSDL and WS-Security; REST is a lighter architectural style using HTTP and usually JSON.

Your code review shows a test class with 30 copy-pasted lines in every method. How do you refactor it with Java features?

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Extract repeated steps into private helper methods or a page object, move common setup into @BeforeMethod, and use a DataProvider when only data differs. If the repeated code differs only in a small action, pass that action as a lambda, such as a Consumer<WebDriver>. Rerun the tests after each small refactor to confirm behaviour is unchanged.

How do you undo a commit that has already been pushed?

Git, Maven and JenkinsMedium

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Use git revert <commit>, which creates a new commit that reverses the changes and keeps history intact, safe for shared branches. git reset moves the branch pointer backwards and is fine for local commits, but resetting and force-pushing a shared branch rewrites history and breaks teammates' clones. If force push is truly needed, use --force-with-lease and tell the team.

Describe a time you automated a manual build or release step for the QA team.

Git, Maven and JenkinsMedium

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Situation: before each regression a tester spent an hour deploying the build to QA and seeding data by hand. Task: remove that manual step. Action: I wrote a Jenkins pipeline stage that deployed the build, ran database seed scripts and a smoke check, then triggered the regression job, and documented it for the team. Result: setup dropped to ten minutes without human effort, and regressions could run overnight automatically.

How do you verify that the correct page has loaded in POM?

Page Object ModelMedium

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Give each page an isAt() or waitUntilLoaded() method that waits for a unique element, page title or URL fragment. Call it in the constructor or right after navigation. If it fails, throw a clear error such as "Expected Cart page but URL was /login". This catches navigation problems at the right point instead of failing later with a confusing locator error.

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

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

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.

Cucumber says a step is undefined even though the step definition exists. How do you fix it?

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Check the glue path in the runner points to the package containing the step classes. Check the step text matches exactly, including quotes and parameter types, since {string} expects quoted text. Confirm the step class is under src/test/java and compiled, the annotation import is io.cucumber.java.en, and the Cucumber versions of core, java and the runner module match. Running with dryRun shows all unmatched steps quickly.

What is a DataProvider in TestNG?

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@DataProvider returns Object[][]; a @Test(dataProvider = "name") method runs once per row — the basis of data-driven tests, often reading Excel or JSON.

What makes a good Gherkin scenario?

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A good scenario describes one behaviour in business language, uses declarative steps ("When the user logs in as a manager") rather than UI clicks ("When I click the login button"), has one When and a clear Then, stays under about 5 to 7 steps and is independent of other scenarios. The title should state the rule being checked so failures are understood without opening the code.

How do you run Appium tests in parallel on several Android devices?

Appium Mobile AutomationHard

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Give each device its own session: unique appium:udid, a separate appium:systemPort for UiAutomator2 and, for hybrid apps, a separate chromedriverPort. Store the driver in a ThreadLocal so threads never share it. Pass device details through TestNG parameters or a DataProvider and run with parallel="tests", one test tag per device. One Appium server can handle several sessions, or use a Selenium Grid 4 with Appium nodes or a cloud device farm for larger matrices.

What is the difference between the normal, eager and none page load strategies in Selenium?

Selenium WebDriverMedium

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Page load strategy decides when navigation commands like get() return. Normal, the default, waits for the full load event including images and stylesheets. Eager returns when the DOM is ready (DOMContentLoaded), which speeds up heavy pages. None returns immediately after the initial response. With eager or none you must rely on explicit waits for the elements you need. Set it through options.setPageLoadStrategy(PageLoadStrategy.EAGER).

Your UI tests run noticeably slower on the Grid than on your laptop. How do you find the cause?

Selenium Grid & DockerHard

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Every command now travels over the network, so chatty code with many findElement calls or getText in loops suffers most. Check latency between test runner and Grid, ideally keeping them in the same network or region. Check node resources: overloaded CPU or many sessions per container slow browsers. Video recording and VNC add overhead. Reduce round trips by batching checks, using JavaScript for bulk reads and avoiding implicit waits combined with explicit ones.

Write a REST Assured test using RequestSpecBuilder and ResponseSpecBuilder.

REST AssuredMedium

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RequestSpecification req = new RequestSpecBuilder() .setBaseUri(Config.baseUrl()) .setContentType(ContentType.JSON) .addHeader("Authorization", "Bearer " + token) .build(); ResponseSpecification ok = new ResponseSpecBuilder() .expectStatusCode(200) .expectContentType(ContentType.JSON) .build(); given().spec(req).when().get("/orders").then().spec(ok);

How do you test an API that returns paginated results?

REST AssuredMedium

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Call the first page, check page size, total count and the next link or cursor. Loop through pages until there is no next page, collecting IDs, then assert no duplicates and the total matches the reported count. Also test edge cases: page 0, a page beyond the last, invalid page size and sorting stability. Cap the loop to avoid endless runs if the API misbehaves.

Chrome inside a Docker node keeps crashing with session deleted because of page crash. How do you fix it?

Selenium Grid & DockerMedium

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This is almost always shared memory exhaustion, because Docker's default /dev/shm of 64 MB is too small for Chrome. Set shm_size: 2gb in Compose or --shm-size=2g in docker run. Also check the container's memory limit and the number of sessions per node, since several browsers in one container multiply memory use. Heavy pages or memory leaks in long sessions can also crash tabs, so restart sessions between test classes.

An API returns a list in random order and your assertion on the first element fails intermittently. How do you fix it?

REST AssuredEasy

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Do not assert on positions when the API does not guarantee order. Use order-independent Hamcrest matchers such as hasItem, hasItems or containsInAnyOrder on the extracted field, for example body("name", hasItems("Pen", "Book")). Or use GPath filtering like find { it.id == 42 } to pick the right item before checking its fields. If order matters for the feature, raise it as a requirement and request a sort parameter.

What can testers do with Chrome DevTools Protocol support in Selenium 4?

Selenium WebDriverHard

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Selenium 4 exposes CDP through the DevTools interface and the newer cross-browser BiDi APIs. Testers can capture console logs and JavaScript errors, intercept or mock network requests, emulate slow networks or geolocation, add basic authentication headers and collect performance metrics. CDP is Chromium-specific and tied to browser versions, so for long-term code prefer WebDriver BiDi features where available, and keep CDP usage behind a small helper class.

How do you run Selenium tests in Docker containers in CI?

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Use official Selenium images, either standalone-chrome for simple runs or a Grid with hub and node containers via Docker Compose. The test container or Jenkins agent points RemoteWebDriver to http://selenium-hub:4444. Containers give the same browser version everywhere and are cleaned after each run. Add shm_size for Chrome stability and record videos for failed tests if needed.

How do you switch between native and webview contexts in a hybrid app?

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// Requires the webview to be debuggable in the app build Set<String> contexts = driver.getContextHandles(); for (String ctx : contexts) { if (ctx.startsWith("WEBVIEW")) { driver.context(ctx); break; } } driver.findElement(By.cssSelector("#email")).sendKeys("qa@test.com"); // back to native controls driver.context("NATIVE_APP");

POST vs PUT vs PATCH?

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POST creates a resource, PUT replaces the whole resource (idempotent) and PATCH updates part of it.

Your UI regression suite has 15 percent flaky failures. How would you bring it under control?

Selenium WebDriverHard

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Measure flakiness per test over many runs and fix the worst first. Typical fixes are replacing sleeps with explicit waits, creating independent test data via API, avoiding shared logins, using stable locators, isolating parallel drivers and stubbing unstable third parties. Quarantine known flaky tests into a separate job so they do not block releases, and set a target like under 2 percent.

How do you publish Allure or Extent reports from Jenkins?

Git, Maven and JenkinsMedium

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For Allure, install the Allure Jenkins plugin, configure the commandline tool, and add allure results: [[path: 'target/allure-results']] in the post always block. For Extent, archive the HTML file and use the HTML Publisher plugin to show it as a build link. Keep report history per build and share the link in failure notifications.

How do you handle test data cleanup in Cucumber scenarios?

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Create data in Given steps through APIs, record the created IDs in the scenario context, and delete them in an @After hook, which runs even when the scenario fails. Use unique names with a timestamp or UUID to avoid clashes in parallel runs. For shared environments, add a nightly cleanup job for leftover data tagged with a test prefix.

How do you take a screenshot on failure in TestNG?

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Implement ITestListener.onTestFailure(): File src = ((TakesScreenshot) driver).getScreenshotAs(OutputType.FILE); then copy it into the reports folder.

You need the same test to support Chrome, Firefox and Edge. How would you design driver creation in Java?

Core Java for TestersHard

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Use a factory: a BrowserType enum and a DriverFactory.create(BrowserType) that returns the right WebDriver with its options, using a switch. Read the browser from a system property with a default. For remote runs, return RemoteWebDriver with the same options. Tests depend only on the WebDriver interface, so adding a new browser changes one class, following the open-closed principle.

Why is XPath slow in Appium and what should you use instead?

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For every XPath query Appium must fetch the full page source of the app, convert it into an XML document and then evaluate the expression, which can take seconds on large screens and is even slower on iOS. Index-based XPath also breaks when layouts change. Use accessibility id first, then resource-id, Android UiAutomator selectors or iOS predicate strings and class chains, which are evaluated natively on the device and are much faster.

A runtime permission pop-up appears on first launch and breaks your Android tests. How do you handle it?

Appium Mobile AutomationEasy

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The cleanest fix is the capability appium:autoGrantPermissions set to true, which grants all permissions the app declares at install time. If you need to test the permission flow itself, handle the dialog explicitly by waiting for the Allow button using its resource-id and clicking it. Another option is granting a specific permission with adb shell pm grant before the test. Avoid blind try-catch around taps, because it hides real failures.

What is data-driven testing?

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Running the same test logic with multiple data sets from Excel, CSV, JSON or a database, so coverage increases without duplicating code.

How do you use Cucumber with REST Assured for API BDD tests?

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Write scenarios in business terms, such as "When a customer places an order for 2 items". In step definitions, build the request with REST Assured, store the Response in a shared scenario context, and assert in Then steps using then().statusCode() and JSON path checks. Keep base URI, auth and specs in a helper class so steps stay short and the same steps serve many features.

An element is visible in Appium Inspector but your test throws NoSuchElementException on the device. What do you check?

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First check timing: the screen may still be loading, so add an explicit wait for presence. Then check context: in a hybrid app the element may be in a webview while you are in NATIVE_APP. Confirm the locator matches exactly, including package prefix in resource-id. The element may be off screen in a list, so scroll first. Also check that the Inspector session used the same app build, language and device size as the test.

Which reporting tools do you use?