01
ArrayList vs HashMap — how do you use them in a framework?
Show answer
ArrayList stores an ordered list (e.g. all product names on a page). HashMap stores key–value pairs (e.g. test data or config properties).
Easy Automation Testing Interview Questions
117 easy questions with answers. Definitions and fundamentals every candidate must answer quickly and correctly.
Topics in the easy set
Core Java for Testers: 19 REST Assured: 13 Selenium WebDriver: 11 Cucumber and BDD: 11 TestNG Framework: 10 API Testing and CI/CD: 10 Git, Maven and Jenkins: 10 Appium Mobile Automation: 9 Selenium Grid & Docker: 9
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02
What locators does Selenium support?
Show answer
id, name, className, tagName, linkText, partialLinkText, CSS selector and XPath. Prefer stable ids or CSS, using XPath when needed.
03
List common TestNG annotations and their order.
Show answer
BeforeSuite, BeforeTest, BeforeClass, BeforeMethod, Test, AfterMethod, AfterClass, AfterTest and AfterSuite.
04
What is an API and what are common HTTP methods?
Show answer
An interface for systems to talk to each other. GET reads, POST creates, PUT replaces, PATCH updates partially and DELETE removes.
05
What are exceptions and how do you handle them?
Show answer
Runtime events that disrupt flow. Use try-catch-finally, throw, throws, and custom exceptions; checked exceptions must be handled while unchecked ones need not be.
06
String vs StringBuilder?
Show answer
String is immutable — every change creates a new object. StringBuilder is mutable and faster for repeated changes (not thread-safe; StringBuffer is).
07
Write an XPath for a button with the text "Login".
Show answer
//button[normalize-space()='Login']
//button[contains(text(),'Login')]
08
Difference between final, finally and finalize?
Show answer
final makes a variable, method or class unchangeable; finally is a block that always runs after try-catch; finalize is a deprecated method called before garbage collection.
09
What is the Page Object Model?
Show answer
A design pattern where each page is a class holding its locators and actions, so tests stay readable and a locator change is fixed in one place.
10
What are wrapper classes in Java?
Show answer
Classes such as Integer and Double that wrap primitive types as objects, needed for collections and for parsing text from web elements.
11
Method overloading vs overriding?
Show answer
Overloading: same method name, different parameters, in the same class (compile time). Overriding: a subclass redefines a parent method with the same signature (runtime polymorphism). WebDriver driver = new ChromeDriver() is runtime polymorphism.
12
Implicit vs explicit vs fluent wait?
Show answer
Implicit wait applies globally to element lookups. Explicit wait waits for a specific condition (WebDriverWait + ExpectedConditions). Fluent wait is an explicit wait with custom polling and ignored exceptions.
13
What is the difference between == and equals() in Java?
Show answer
== compares references (or primitive values); equals() compares content when overridden, as in String.
14
Difference between an abstract class and an interface?
Show answer
An abstract class can hold state and concrete methods; an interface defines a contract (with default methods since Java 8). A class extends one abstract class but can implement many interfaces.
15
What is WebDriver and how does it communicate with the browser?
Show answer
WebDriver sends commands over HTTP (W3C protocol) to a browser-specific driver such as chromedriver, which controls the actual browser.
16
What is the execution order of TestNG annotations?
Show answer
@BeforeSuite → @BeforeTest → @BeforeClass → @BeforeMethod → @Test → @AfterMethod → @AfterClass → @AfterTest → @AfterSuite.
17
findElement vs findElements?
Show answer
findElement returns the first match and throws NoSuchElementException if nothing is found. findElements returns a List (empty if nothing is found) — handy to check whether an element exists.
18
What is Selenium and what are its components?
Show answer
An open-source suite for browser automation: WebDriver, IDE, Grid and the older RC. WebDriver controls browsers through their native drivers.
19
What are the main OOP concepts in Java?
Show answer
Encapsulation, inheritance, polymorphism and abstraction. Testers use them to build reusable page classes, base tests and utility libraries.
20
Common HTTP status codes?
Show answer
200 OK, 201 Created, 204 No Content, 400 Bad Request, 401 Unauthorized, 403 Forbidden, 404 Not Found, 500 Internal Server Error.
21
What is the purpose of testng.xml?
Show answer
A configuration file to define suites, tests, classes, groups, parameters and parallel execution settings.
22
What is TestNG and why is it used with Selenium?
Show answer
A test framework offering annotations, grouping, prioritisation, parallel runs, data providers and reports, which structure and scale Selenium tests.
23
What is JSON and how is it used in API testing?
Show answer
A lightweight text format of key-value pairs and arrays used in API requests and responses, validated field by field in tests.
24
What do HTTP status codes 200, 201, 400, 401, 403, 404 and 500 mean?
Show answer
200 OK, 201 Created, 400 bad request, 401 unauthenticated, 403 forbidden, 404 not found and 500 server error.
25
Reverse a string in Java.
Show answer
String r = new StringBuilder(s).reverse().toString();
// or loop from the last index and append each character
26
What is Gherkin and what are its main keywords?
Show answer
Gherkin is the plain-English language Cucumber uses to describe behaviour. Main keywords are Feature, Scenario, Given (precondition), When (action), Then (expected outcome), And/But (continuation), Background (common steps), Scenario Outline with Examples (data-driven), and Rule (groups scenarios under one business rule). Because it is readable by business analysts and testers alike, the feature file becomes living documentation as well as an executable test.
27
What is the difference between Scenario and Scenario Outline in Cucumber?
Show answer
A Scenario runs once with fixed values. A Scenario Outline is a template with placeholders in angle brackets, and an Examples table supplies rows of data, so the same steps run once per row. Use an Outline when only the data changes, such as testing login with valid, locked and expired users. Avoid huge Examples tables; if data grows large, move it to an external source.
28
What is a step definition in Cucumber?
Show answer
A step definition is a Java method annotated with @Given, @When or @Then whose expression matches a Gherkin step. When Cucumber runs a feature, it finds the matching method and executes it, passing captured parameters as arguments. Keep step definitions thin: they should call page objects or API helpers rather than contain Selenium code directly, so the same steps stay reusable across many features.
29
How do you run only selected scenarios using tags in Cucumber?
Show answer
Add tags like @smoke or @regression above a Feature or Scenario, then filter with a tag expression. In the runner use @ConfigurationParameter(key = FILTER_TAGS_PROPERTY_NAME, value = "@smoke and not @wip") with the JUnit Platform engine, or pass -Dcucumber.filter.tags="@smoke" from Maven. Tag expressions support and, or, not and brackets, so CI can run smoke on every commit and regression nightly.
30
What is the Cucumber runner class and what does it configure?
Show answer
The runner tells the test engine where features and glue code are and how to report. With JUnit 5 it uses @Suite, @IncludeEngines("cucumber"), @SelectClasspathResource("features") and @ConfigurationParameter for glue, plugins and tags. With TestNG you extend AbstractTestNGCucumberTests and use @CucumberOptions(features, glue, tags, plugin, monochrome). The runner lets Maven or Jenkins run features like normal tests.
31
What are the three amigos in BDD?
Show answer
The three amigos are the business representative (product owner or BA), the developer and the tester, who meet before development to discuss a story. They agree on rules and concrete examples, which become Gherkin scenarios. The meeting catches misunderstandings early, before code is written. Cucumber automation is the output, but the conversation is the real value of BDD.
32
What is dryRun in Cucumber and when do you use it?
Show answer
dryRun=true makes Cucumber parse all feature files and check every step has a matching definition without actually executing anything. It is fast and is useful after writing new features, during refactoring, or as a quick CI gate to catch undefined or ambiguous steps. It also prints snippets for missing step definitions that you can paste and implement.
33
How do you generate reports from Cucumber?
Show answer
Configure plugins such as pretty for console, html:target/cucumber.html for a built-in report and json:target/cucumber.json for tools. The JSON feeds maven-cucumber-reporting or the Jenkins Cucumber Reports plugin. For richer dashboards, add the Allure or Extent Cucumber adapter. Attach screenshots and logs in hooks so failures can be analysed from the report alone.
34
Write a Scenario Outline for login with three data sets.
Show answer
Scenario Outline: Login with different users
Given the user is on the login page
When the user logs in with "<username>" and "<password>"
Then the message "<message>" is shown
Examples:
| username | password | message |
| asha | Valid@1 | Welcome Asha |
| asha | wrong | Invalid password |
| locked1 | Valid@1 | Account is locked |
35
Explain the given-when-then structure in REST Assured.
Show answer
given() sets up the request: headers, params, body, auth. when() performs the HTTP call such as get(), post(), put() or delete(). then() validates the response: status code, headers, body using Hamcrest matchers, and response time. You can call extract() after then() to pull values for later steps. The fluent structure reads like a test specification and keeps setup, action and checks clearly separate.
36
Write a REST Assured POST test that sends a JSON body and checks the response.
Show answer
@Test
public void createUser() {
String body = "{\"name\":\"Ravi\",\"job\":\"QA\"}";
given()
.baseUri("https://api.example.com")
.contentType(ContentType.JSON)
.body(body)
.when()
.post("/users")
.then()
.statusCode(201)
.body("name", equalTo("Ravi"))
.body("id", notNullValue());
}
37
What is the difference between path params and query params in REST Assured?
Show answer
Path params are part of the URL path and identify a resource, such as /users/{id}; you set them with pathParam("id", 5). Query params come after ? and filter or modify the result, such as /users?page=2; you set them with queryParam("page", 2). REST Assured URL-encodes both. Using named params instead of string concatenation makes tests cleaner and safer.
38
How do you extract a value from one response and use it in the next request?
Show answer
String token = given().body(creds).when().post("/login")
.then().statusCode(200)
.extract().path("token");
given()
.header("Authorization", "Bearer " + token)
.when()
.get("/orders")
.then()
.statusCode(200);
39
How do you log requests and responses in REST Assured?
Show answer
Use given().log().all() for the full request and then().log().all() for the full response. To reduce noise, use log().ifValidationFails() on both, which prints only when a test fails. For a whole suite, set RestAssured.enableLoggingOfRequestAndResponseIfValidationFails() or add RequestLoggingFilter and ResponseLoggingFilter in a shared spec. Mask tokens and passwords before logs reach CI.
40
How do you measure and assert API response time in REST Assured?
Show answer
Use then().time(lessThan(2000L)) for a quick check or response.getTimeIn(TimeUnit.MILLISECONDS) to log the value. This measures client-side time, including network, so set generous thresholds and treat it as a smoke signal, not a performance test. For real load and latency percentiles, use tools such as JMeter, Gatling or k6.
41
What is the difference between extract().response() and extract().path()?
Show answer
extract().response() returns the full Response object, so you can read status, headers, cookies, body as string, and use jsonPath() several times. extract().path("field") returns one value directly from the body. Use path() when you need a single value like an id or token, and response() when you need many details or want to log the response.
42
How do you send form parameters and headers in REST Assured?
Show answer
Use formParam("username", "asha") and formParam("password", "pass") for application/x-www-form-urlencoded bodies; REST Assured sets the content type for you. Add headers with header("X-Client", "web") or headers(map) for many at once. Cookies use cookie(name, value). Keep common headers in a RequestSpecification so individual tests only add what is specific to them.
43
How do you validate response headers and cookies in REST Assured?
Show answer
Use then().header("Content-Type", containsString("application/json")) and then().cookie("sessionId", notNullValue()). To read values, use response.getHeader("X-Request-Id") or response.getCookie("sessionId"). Header checks matter for caching, security headers like Strict-Transport-Security, and correlation IDs used when debugging failures across services. Also assert that sensitive headers such as server version details are not exposed.
44
What is the Page Object Model and what problem does it solve?
Show answer
POM is a design pattern where each page or component of the application has a class holding its locators and the actions a user can perform there, such as login() or searchProduct(). Tests call these methods instead of using Selenium directly. When the UI changes, you update one page class instead of dozens of tests, which reduces duplication and makes tests readable.
45
Write a simple page object class for a login page.
Show answer
public class LoginPage {
private final WebDriver driver;
private final By user = By.id("username");
private final By pass = By.id("password");
private final By submit = By.cssSelector("button[type='submit']");
public LoginPage(WebDriver driver) { this.driver = driver; }
public HomePage loginAs(String u, String p) {
driver.findElement(user).sendKeys(u);
driver.findElement(pass).sendKeys(p);
driver.findElement(submit).click();
return new HomePage(driver);
}
}
46
How do you structure packages in a Selenium POM framework?
Show answer
A common layout: src/main/java with pages, components, base, utils, config and drivers packages; src/test/java with tests grouped by feature, plus listeners; src/test/resources with testng.xml, config properties per environment, test data and log configuration. Keep framework code separate from tests so it can be reused, and keep each package focused on one responsibility.
47
What locator strategy do you follow inside page objects?
Show answer
Prefer stable attributes in this order: dedicated test attributes like data-testid, id, name, then short CSS selectors, and XPath only when text or complex relationships are needed. Avoid absolute XPaths and index-based locators. Keep locators as private final By fields at the top of the class with clear names, so updates are quick and readable.
48
What is the difference between git fetch and git pull?
Show answer
git fetch downloads new commits and branches from the remote but does not change your working files; you can inspect them with git log origin/main. git pull is fetch followed by merge (or rebase if configured) into your current branch. Fetch is safer when you want to review changes before integrating them.
49
How do you resolve a merge conflict in Git?
Show answer
Git marks conflicting sections with <<<<<<<, ======= and >>>>>>>. Open each file, decide which change to keep or combine both, remove the markers, then git add the files and complete with git commit (or git rebase --continue). Run the affected tests before pushing. Pull often and keep branches short-lived to reduce conflicts.
50
What is a .gitignore file and what should an automation project ignore?
Show answer
A .gitignore lists files Git should not track. In a Java automation project ignore target/, test-output/, allure-results/, reports, screenshots, logs, IDE folders like .idea and .vscode, *.iml, OS files like .DS_Store, and local config files holding secrets. Ignoring generated output keeps the repository small and avoids noisy diffs and conflicts.
51
What is git stash and when would you use it?
Show answer
git stash saves uncommitted changes and cleans the working directory so you can switch branches. Later, git stash pop reapplies them. Use it when you are halfway through a change and must quickly fix something on another branch. git stash list shows saved stashes, and git stash push -m "msg" names them. For longer work, a temporary commit on a branch is clearer.
52
What is the Maven build lifecycle?
Show answer
The default lifecycle has phases in order: validate, compile, test, package, verify, install and deploy. Running a phase runs all earlier phases too, so mvn test compiles and then runs unit tests through Surefire. mvn verify also runs integration tests with Failsafe. There are also clean and site lifecycles. Automation suites usually run with mvn clean test or mvn clean verify.
53
How do you pass parameters like browser and environment from Maven to your tests?
Show answer
Pass system properties on the command line, for example mvn test -Dbrowser=firefox -Denv=qa. Read them in Java with System.getProperty("browser", "chrome"), giving a default. Surefire forwards -D properties to the forked test JVM, or you can declare them under systemPropertyVariables. Jenkins can expose these as build parameters so testers choose browser and environment per run.
54
How do you trigger a Jenkins job automatically?
Show answer
Common triggers are webhooks from GitHub, GitLab or Bitbucket on push or pull request, cron schedules with triggers { cron('H 2 * * *') } for nightly regression, polling SCM (less efficient), and upstream jobs completing, such as running tests after a deploy job. Multibranch pipelines automatically create jobs for each branch and pull request containing a Jenkinsfile.
55
What is the post section in a Jenkins declarative pipeline?
Show answer
post defines steps that run after stages based on the result: always, success, failure, unstable, changed, fixed and cleanup. In test pipelines, always publishes JUnit results and archives screenshots and reports, failure sends a Slack or email alert, and cleanup removes the workspace. Putting reporting in post ensures results are saved even when tests fail.
56
What does a good commit message look like?
Show answer
A short summary line under about 60 characters in the imperative mood, like "Add retry for flaky payment test", followed by a blank line and a body explaining why the change was made if not obvious. Reference the ticket ID. Small focused commits with clear messages make reviews faster and help when using git log or git bisect to find when a test broke.
57
What is API testing and why is it done before UI testing?
Show answer
API testing checks the business logic layer directly by sending requests and validating responses, status codes, data and errors. It is faster, more stable and cheaper to maintain than UI tests, and it can start as soon as endpoints exist, before the UI is ready. Most functional rules should be covered at API level, leaving UI tests for key user journeys.
58
What is the test pyramid and how does it guide automation?
Show answer
The pyramid suggests many fast unit tests at the base, fewer API or service tests in the middle and a small number of UI end-to-end tests at the top. Lower-level tests are faster and less flaky. An inverted pyramid with mostly UI tests leads to slow, brittle pipelines. Use it as a guide to put each check at the cheapest level that still catches the bug.
59
What is the difference between continuous delivery and continuous deployment?
Show answer
In continuous delivery every change that passes the pipeline is ready to release, but a person approves the production deployment. In continuous deployment every passing change is released to production automatically. Continuous deployment requires very reliable automated tests and monitoring, because there is no manual check before users see the change.
60
What is shift-left testing?
Show answer
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.
61
What is a smoke test versus a sanity test in a pipeline?
Show answer
A smoke test is a broad, shallow check that the build is stable enough for further testing, such as the app launches, login works and main pages load. A sanity test is a narrow check after a specific fix or change to confirm it works. In pipelines, smoke runs on every deploy as a gate; sanity checks are targeted runs for a particular change.
62
How do you test that a method throws an expected exception in TestNG?
Show answer
Use @Test(expectedExceptions = IllegalArgumentException.class) and optionally expectedExceptionsMessageRegExp to check the message. The test passes only if that exception is thrown. For more control, use Assert.assertThrows(IllegalArgumentException.class, () -> service.withdraw(-5)), which returns the exception so you can inspect it further. This style is clearer because the check applies to one line, not the whole test.
63
How do you include and exclude groups in testng.xml?
Show answer
Inside a <test>, add <groups><run><include name="smoke"/><exclude name="broken"/></run></groups>. Only methods in the included groups run, minus excluded ones. Configuration methods must have alwaysRun = true or belong to the groups, or they will be skipped. You can also pass -Dgroups=smoke from Maven Surefire for CI selection.
64
What is the timeOut attribute in TestNG?
Show answer
@Test(timeOut = 5000) fails the test if it runs longer than 5000 milliseconds. It can also be set at suite or test level in testng.xml. It protects pipelines from hanging tests, for example a stuck network call. It is not a performance test; use reasonable limits so slow but correct environments do not cause false failures.
65
An API returns 200 but your REST Assured assertion on a field fails with a null value. How do you debug it?
Show answer
Log the full response with then().log().all() to see the actual body. Common causes are a wrong JSON path, such as missing a wrapper like data, the field being in an array needing an index, a different content type like XML or HTML error page, or the field name having different case. Fix the path, and add a schema check so structure changes are caught clearly.
66
Write a REST Assured test for a DELETE request followed by a check that the resource is gone.
Show answer
@Test
public void deleteUser() {
int id = createTestUser();
given().spec(req).pathParam("id", id)
.when().delete("/users/{id}")
.then().statusCode(204);
given().spec(req).pathParam("id", id)
.when().get("/users/{id}")
.then().statusCode(404);
}
67
Write a REST Assured PUT test that updates a resource using a POJO.
Show answer
@Test
public void updateUser() {
User update = new User("Ravi", "Lead QA");
given().spec(req)
.pathParam("id", 7)
.body(update)
.when()
.put("/users/{id}")
.then()
.statusCode(200)
.body("job", equalTo("Lead QA"));
}
68
Write a DataProvider that supplies two sets of login data and a test that uses it.
Show answer
@DataProvider(name = "logins")
public Object[][] logins() {
return new Object[][] {
{"asha", "Valid@1", true},
{"asha", "wrong", false}
};
}
@Test(dataProvider = "logins")
public void login(String user, String pass, boolean ok) {
boolean result = loginPage.loginAs(user, pass).isLoggedIn();
Assert.assertEquals(result, ok);
}
69
Tell me about a time you found a critical bug through automation.
Show answer
Situation: during a sprint, my nightly regression showed checkout failing only for one payment option. Task: confirm if it was a test issue or a real bug. Action: I reproduced it manually, checked the API response and found a wrong tax value, then logged a clear defect with steps, logs and screenshots. Result: developers fixed it before the release and the test was added to the smoke suite.
70
How did you handle it when your test estimates turned out to be wrong in a sprint?
Show answer
Situation: I estimated three days to automate a new module, but the UI had complex dynamic tables. Task: still deliver what the sprint needed. Action: I told the lead early on day two, proposed automating the API checks first and the UI flows next sprint, and documented the extra effort. Result: the sprint goal was met, and I now spike unfamiliar screens before estimating.
71
Your framework throws NullPointerException in a page object on the first action. What are the likely causes?
Show answer
The driver was never initialised or was passed as null, for example a page created before setup ran or a static driver not yet assigned. With PageFactory, initElements may not have been called, so @FindBy fields are null. A config value read from a properties file may also be missing. Check the stack trace line, then fix the setup order and add null checks with clear messages.
72
A teammate compares two strings with == and the test sometimes passes and sometimes fails. Explain.
Show answer
== compares object references, not content. String literals are interned, so two literals with the same text may share a reference and == returns true, but strings read from the UI or built at runtime are new objects, so == returns false even with the same text. Use equals() or equalsIgnoreCase() for content, and Objects.equals() to be null-safe.
73
Your helper catches Exception and prints the stack trace, and tests pass even when steps fail. What is the issue?
Show answer
Swallowing exceptions hides failures, so TestNG never sees an error and marks the test passed. Catch only specific exceptions you can handle, add context and rethrow, or let them propagate. If you need logging, log and then throw. Code reviews should flag empty catch blocks and broad catch (Exception e) in test code.
74
Write Java code to find duplicate elements in a list.
Show answer
List<String> names = List.of("Asha", "Ravi", "Asha", "Neha", "Ravi");
Set<String> seen = new HashSet<>();
Set<String> dupes = new LinkedHashSet<>();
for (String n : names) {
if (!seen.add(n)) {
dupes.add(n);
}
}
System.out.println(dupes); // [Asha, Ravi]
75
Write Java code to count the occurrences of each character in a string.
Show answer
String s = "automation";
Map<Character, Integer> counts = new LinkedHashMap<>();
for (char c : s.toCharArray()) {
counts.put(c, counts.getOrDefault(c, 0) + 1);
}
System.out.println(counts);
// a=2, u=1, t=2, o=2, m=1, i=1, n=1
76
Tell me about a time you had to learn Java quickly for an automation role.
Show answer
Situation: I moved from manual testing into an automation team using Java. Task: become productive within a month. Action: I practised core Java daily, focusing on OOP, collections and exceptions, solved small coding problems, and read the existing framework code with a senior's help. Result: in four weeks I was writing page objects and tests that passed review, and I kept learning streams afterwards.
77
How do you keep your Java and automation skills up to date?
Show answer
Situation: tools change fast, and my team was still on older Selenium and Java versions. Task: keep myself and the framework current. Action: I follow release notes, try new features in a small personal project, and present one useful change to the team each quarter, such as moving to java.time or Selenium 4 relative locators. Result: we upgraded smoothly and I became the go-to person for upgrades.
78
Describe a time you received critical feedback on your test code.
Show answer
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.
79
Write Selenium code to wait for a loader to disappear and then click a button.
Show answer
WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(15));
wait.until(ExpectedConditions.invisibilityOfElementLocated(
By.cssSelector(".spinner")));
wait.until(ExpectedConditions.elementToBeClickable(
By.id("placeOrder"))).click();
80
Selenium's driver version suddenly mismatches the browser version on agents. How do you prevent this?
Show answer
Use Selenium Manager, built into Selenium 4.6 and later, which resolves the right driver automatically, so you do not commit driver binaries. In CI, pin browser versions using Docker images or browser options so all agents match. Avoid auto-updating browsers on test agents. Log the browser and driver versions at the start of each run to diagnose quickly.
81
Why do you want to work as an automation tester rather than a manual tester?
Show answer
Situation: in my internship I repeated the same regression checks every release. Task: I wanted to free time for exploratory testing. Action: I learnt Selenium and Java and automated our login and search regression in my spare time. Result: the checks went from two hours to ten minutes, and I realised I enjoy building tools that improve quality, which is why I want this role.
82
What is Appium and how does its architecture work?
Show answer
Appium is an open-source tool for automating native, hybrid and mobile web apps on Android and iOS using the W3C WebDriver protocol. Your Java test sends HTTP commands to the Appium server, which forwards them to a platform driver such as UiAutomator2 for Android or XCUITest for iOS. That driver talks to the device and returns results. Because it follows WebDriver, Selenium testers can reuse locators, waits and framework design.
83
What is the difference between native, hybrid and mobile web apps from a testing point of view?
Show answer
A native app is built with platform SDKs and is tested through native locators like accessibility id or resource-id. A mobile web app runs in the device browser, so you automate it much like desktop Selenium with mobile Chrome or Safari. A hybrid app wraps web content inside a native shell, so tests switch between the NATIVE_APP context and a WEBVIEW context. Knowing the type decides your driver, locators and setup.
84
What are Appium capabilities and which ones are essential to start a session?
Show answer
Capabilities are key-value settings sent when creating a session that tell Appium what to automate. Essential ones are platformName, appium:automationName (UiAutomator2 or XCUITest), appium:deviceName or appium:udid, and either appium:app (path to the apk or ipa) or appPackage and appActivity for an installed Android app. In Appium 2 non-standard capabilities need the appium: prefix. In Java you usually set them through UiAutomator2Options or XCUITestOptions.
85
Which locator strategies does Appium support and which should you prefer?
Show answer
Appium supports accessibility id, id (resource-id on Android), class name, XPath, Android UiAutomator selectors, iOS predicate strings and iOS class chains. Prefer accessibility id because it is fast, works across Android and iOS and also improves app accessibility. Next use resource-id or iOS predicates. Use XPath only as a last resort because it walks the whole UI tree and is slow and brittle, especially on iOS.
86
Your team asks whether mobile tests should run on emulators or real devices. What do you recommend?
Show answer
Use both, for different purposes. Emulators and simulators are cheap, fast to reset and easy to run in CI, so they suit smoke and regression runs on every commit. Real devices reveal issues emulators hide: performance on low-end hardware, camera, biometrics, push notifications, network changes and vendor-specific Android skins. A common plan is emulators in the pull request pipeline and a nightly run on a small matrix of real devices covering the most-used models.
87
What are appPackage and appActivity in Android automation?
Show answer
appPackage is the unique application id of an Android app, such as com.example.shop, and appActivity is the activity screen that Appium launches first, such as .MainActivity. Together they let Appium start an app that is already installed without passing the apk path. You can find them with adb shell dumpsys window or by reading the manifest. A wrong activity name is a common reason a session fails to start.
88
What is Appium Inspector and how do you use it?
Show answer
Appium Inspector is a desktop or web tool that connects to an Appium server with your capabilities and shows a live screenshot of the app with its element tree. Clicking an element shows its attributes such as accessibility id, resource-id, text and bounds, and suggests locators. You can also try taps and swipes interactively. Testers use it to find stable locators and to check whether an element is really present before writing code.
89
A runtime permission pop-up appears on first launch and breaks your Android tests. How do you handle it?
Show answer
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.
90
The on-screen keyboard hides the login button in your mobile test. What do you do?
Show answer
Call driver.hideKeyboard() after typing, or check driver.isKeyboardShown() first so the call does not fail when no keyboard is open. On Android you can also set appium:hideKeyboard or use a capability for the unicode keyboard so the soft keyboard does not appear. Alternatively press the keyboard's Done or Enter key, or scroll the button into view. Pick one approach and put it in a helper so all tests behave the same.
91
Write Java code to find the second largest number in an integer array.
Show answer
public static int secondLargest(int[] nums) {
int first = Integer.MIN_VALUE, second = Integer.MIN_VALUE;
for (int n : nums) {
if (n > first) {
second = first;
first = n;
} else if (n > second && n != first) {
second = n;
}
}
if (second == Integer.MIN_VALUE) throw new IllegalArgumentException("No second largest");
return second;
}
92
An assertion on element text fails even though the text looks identical on screen. What could be the reason?
Show answer
The text may contain extra whitespace, a line break or a non-breaking space that looks normal visually. getText() also returns only visible text and applies CSS text-transform, so uppercase styling changes the value. Print the string with its length or character codes to spot hidden characters. Fix it by trimming and normalising whitespace before comparing, or compare with the expected case-insensitively when the UI uses text-transform.
93
What is RemoteWebDriver and how is it different from ChromeDriver?
Show answer
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.
94
What is the difference between a Docker image and a container?
Show answer
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.
95
What is Docker Compose and why is it useful for Selenium Grid?
Show answer
Docker Compose lets you define several containers, their images, ports, environment variables and networks in one docker-compose.yml file and start them together with docker compose up. For Selenium it means a hub plus Chrome, Firefox and Edge nodes, and even the application under test, start with one command on any laptop or CI agent. The file is version-controlled, so every tester and pipeline uses the same Grid setup.
96
How do you watch a test running inside a Docker Selenium container?
Show answer
The selenium node and standalone images include a VNC server and noVNC. Expose port 7900 and open http://localhost:7900 in a browser; the default password is secret, or set SE_VNC_NO_PASSWORD to skip it. You can also open the Grid UI on port 4444 and click the session's video icon. This is very useful for debugging tests that fail only inside the container, such as layout or focus problems.
97
Write Java code to create a RemoteWebDriver for a Selenium Grid using ChromeOptions.
Show answer
String gridUrl = System.getProperty("grid.url", "http://localhost:4444");
ChromeOptions options = new ChromeOptions();
options.addArguments("--window-size=1920,1080");
options.setCapability("se:name", "Login smoke test");
WebDriver driver = new RemoteWebDriver(new URL(gridUrl), options);
try {
driver.get("https://app.test/login");
} finally {
driver.quit();
}
98
How do you check that the Grid is ready before starting the tests in CI?
Show answer
Poll the Grid status endpoint, http://hub:4444/status, until the JSON field value.ready is true, which means at least one node has registered. In a shell step you can loop with curl and jq, for example until curl -s http://localhost:4444/status | jq -e '.value.ready'; do sleep 2; done, with an overall timeout. In Compose you can add a healthcheck on the hub. Without this, the first tests fail while nodes are still starting.
99
How do you increase the number of Chrome nodes with Docker Compose?
Show answer
Use the scale option: docker compose up -d --scale chrome=4 starts four Chrome node containers from the same service definition, and each registers with the hub. Do not fix container names or host ports on a scaled service, or the extra containers will clash. Check the Grid UI on port 4444 to confirm the slots. Make sure the host has enough CPU and memory, roughly one CPU core and 1 to 2 GB per browser.
100
How do you start a standalone Chrome container and run your tests against it?
Show answer
Run docker run -d -p 4444:4444 -p 7900:7900 --shm-size=2g selenium/standalone-chrome:latest, preferably with a pinned version tag instead of latest. It starts a mini Grid with one Chrome node. Point RemoteWebDriver to http://localhost:4444 with ChromeOptions and the tests run inside the container. Port 7900 lets you watch through noVNC. Stop it with docker stop when finished, or use --rm so it is removed automatically.
101
You configured 50 parallel threads but only 8 tests run at a time on the Grid. Why?
Show answer
The Grid only has 8 free slots, so the other requests wait in the New Session Queue. Total parallelism equals nodes multiplied by max sessions per node, not the TestNG thread count. Check the Grid UI for slot count. To run more, scale the node containers, raise max sessions if hardware allows, or use a larger grid. Otherwise reduce threads to match slots so waiting requests do not time out.
102
What are stubs, mocks, fakes and spies in testing?
Show answer
They are test doubles that replace real dependencies. A stub returns fixed answers, such as a fake API returning a canned user. A mock also verifies how it was called, like checking a payment service received one charge. A fake is a lightweight working version, such as an in-memory database. A spy wraps a real object and records calls. Automation testers often use WireMock stubs to isolate tests from unstable services.
103
What is the Rule keyword in Gherkin?
Show answer
Rule, added in Gherkin 6, groups scenarios that illustrate one business rule inside a feature. For example, a Feature: Discounts can have Rule: Orders above 1000 get free delivery, followed by scenarios showing the rule holding and not holding. Each Rule can have its own Background. It makes feature files read like a specification of rules with examples, which helps business stakeholders see exactly what each scenario proves.
104
Some scenarios are still being developed and must not run in CI yet. How do you handle them?
Show answer
Tag them, for example with @wip, and exclude the tag in the CI runner using a tag expression like not @wip, set through the cucumber.filter.tags property or the runner options. Developers can still run them locally by including the tag. Review @wip scenarios regularly so they do not stay parked forever, and never use the tag to hide failing tests that should be fixed or reported as bugs.
105
What is a Jenkins agent and how do labels help run tests?
Show answer
An agent is a machine or container that runs build steps on behalf of the Jenkins controller. Labels are tags given to agents, such as linux, docker or windows-chrome. In a pipeline, agent { label 'docker' } sends the job to a matching agent. Testers use labels to send UI tests to agents with browsers or Docker installed, and to keep heavy test runs off the controller, which should only coordinate.
106
What is performance testing and what are its main types?
Show answer
Performance testing checks how fast, stable and scalable a system is under a given workload. Load testing measures behaviour at expected traffic. Stress testing pushes beyond capacity to find the breaking point and how the system recovers. Spike testing applies sudden jumps in users. Soak or endurance testing runs normal load for hours to find leaks. Scalability testing checks whether adding resources increases capacity as expected.
107
What are the main elements of a JMeter test plan?
Show answer
A test plan contains Thread Groups that simulate users, Samplers such as HTTP Request that send requests, Config Elements like HTTP Request Defaults, CSV Data Set Config and Header Manager, Logic Controllers that control flow, Timers that add think time, Pre and Post Processors that prepare data or extract values, Assertions that validate responses, and Listeners that collect results. Elements apply according to their scope in the tree.
108
What do number of threads, ramp-up period and loop count mean in a JMeter Thread Group?
Show answer
Number of threads is how many virtual users run in parallel. Ramp-up period is the time JMeter takes to start all of them, so 100 threads with a 50-second ramp-up starts two users per second. Loop count is how many times each user repeats the samplers, or you can set a duration instead. A gradual ramp-up avoids an unrealistic burst at the start and shows where response times begin to degrade.
109
What are JMeter listeners and why should you avoid most of them during a load run?
Show answer
Listeners collect and display results, such as View Results Tree, Summary Report and Aggregate Report. Visual listeners keep every sample in memory and redraw graphs, which consumes a lot of CPU and RAM and can make JMeter itself the bottleneck. During real load runs disable them, run in non-GUI mode, write raw results to a JTL file and generate the HTML dashboard afterwards. Use View Results Tree only for debugging.
110
What is parameterization in JMeter and how does CSV Data Set Config work?
Show answer
Parameterization replaces hard-coded inputs with varied test data so users do not all log in as the same account or search the same item, which would give unrealistic cache hits. CSV Data Set Config reads a CSV file line by line and stores columns into variables like ${username} and ${password}. You set the file path, variable names, delimiter, whether to recycle at end of file and the sharing mode across threads.
111
What are timers in JMeter and why is think time important?
Show answer
By default JMeter fires requests back to back, which is far more aggressive than real users who read pages and fill forms. Timers add delays: Constant Timer, Uniform Random Timer and Gaussian Random Timer add think time, while Constant Throughput Timer and Precise Throughput Timer control request rate. Realistic think time makes the user count meaningful; without it, 100 threads may generate the load of thousands of real users.
112
Why should JMeter load tests be run in non-GUI mode?
Show answer
The GUI is meant for building and debugging scripts. During a run it consumes significant memory and CPU to render the tree and listeners, which limits how many threads one machine can generate and can distort response times. Non-GUI mode, started with jmeter -n, uses far fewer resources, is scriptable in CI and writes results to a file. The JMeter GUI itself shows a warning recommending this.
113
Write the command to run a JMeter test in non-GUI mode and generate the HTML report.
Show answer
# -n non-GUI, -t test plan, -l results file, -e -o HTML dashboard folder
jmeter -n -t tests/checkout.jmx \
-l results/checkout.jtl \
-e -o results/html-report \
-Jusers=100 -Jrampup=60 -Jduration=600
# generate a report later from an existing JTL
jmeter -g results/checkout.jtl -o results/html-report-2
114
How do you record a JMeter script with the HTTP(S) Test Script Recorder?
Show answer
Add the recorder from Templates using the Recording template, which also creates a Thread Group and Recording Controller. Start the recorder on port 8888, set your browser or system proxy to localhost:8888 and import the ApacheJMeterTemporaryRootCA certificate so HTTPS works. Perform the user journey, then stop. Afterwards remove static resources and third-party calls, add correlation for dynamic values, parameterize data and add think time.
115
An API returns a list in random order and your assertion on the first element fails intermittently. How do you fix it?
Show answer
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.
116
What is the difference between a page object and a utility class in a test framework?
Show answer
A page object models one screen or component: its locators and the user actions possible there, such as LoginPage.loginAs. A utility class holds generic helpers not tied to any page, such as reading config, generating test data, date formatting or taking screenshots. Mixing them makes page objects bloated and utilities dependent on the UI. Keep page objects in a pages package and helpers in a utils package.
117
A cookie consent banner appears randomly and blocks clicks in your Selenium tests. How do you handle it?
Show answer
The most stable fix is preventing it: set the consent cookie before the test with driver.manage().addCookie after opening the domain, or ask developers for a test flag that disables the banner. If it must be handled in the UI, write one helper that checks for the banner with a short wait using findElements and closes it if present. Call it from the BasePage after navigation, not scattered in tests.
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