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Technology

Scenario-Based

Difficulty

Advanced

Experience

3-5 Years

Type

Scenario-Based

AutomateQA Team

QA Automation Engineers

June 15, 2026

Interview Question

Your Selenium test is flaky — it sometimes passes and sometimes fails. How do you fix it?

Q: Your Selenium test is flaky — it sometimes passes and sometimes fails. How do you fix it?

Fixing Flaky Selenium Tests Flaky tests are the 1 pain point in automation. They destroy trust in the test suite. Here is a systematic approach to diagnose and fix them. Root Cause 1 — Timing / Race Conditions (Most Common) java // Bad — fixed sleep Thread.sleep(3000); // Good — wait for specific condition WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(15)); wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("result"))); Root Cause 2 — Stale Element Reference java // Bad — reusing stored reference across actions WebElement btn = driver.findElement(By.id("submit")

Answer

Fixing Flaky Selenium Tests

Flaky tests are the #1 pain point in automation. They destroy trust in the test suite. Here is a systematic approach to diagnose and fix them.

Root Cause 1 — Timing / Race Conditions (Most Common)

Java

// Bad — fixed sleep
Thread.sleep(3000);

// Good — wait for specific condition
WebDriverWait wait = new WebDriverWait(driver, Duration.ofSeconds(15));
wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("result")));

Root Cause 2 — Stale Element Reference

Java

// Bad — reusing stored reference across actions
WebElement btn = driver.findElement(By.id("submit"));
performIntermediateAction(); // DOM may update
btn.click(); // may be stale

// Good — find fresh before each use
performIntermediateAction();
driver.findElement(By.id("submit")).click();

Root Cause 3 — Test Data Dependency / Order

Java

// Bad — tests share state
// Test B depends on Test A creating data

// Good — each test creates its own data
@BeforeMethod
public void createTestData() {
    // Create fresh user/order via API
}

@AfterMethod
public void cleanupTestData() {
    // Delete test data
}

Root Cause 4 — Hardcoded Waits in Loops

Java

// FluentWait with polling handles intermittent element appearance
Wait<WebDriver> fluentWait = new FluentWait<>(driver)
    .withTimeout(Duration.ofSeconds(30))
    .pollingEvery(Duration.ofMillis(300))
    .ignoring(StaleElementReferenceException.class)
    .ignoring(NoSuchElementException.class);

Root Cause 5 — Environment Differences

✓Use WebDriverManager to auto-match browser/driver versions
✓Pin browser versions in CI Docker image
✓Use relative file paths, not absolute
✓Externalize environment URLs via properties/env vars

Retry Failed Tests (Short-Term Fix)

In testng.xml:

XML

<suite name="Regression" verbose="1">
    <test name="Tests" preserve-order="true">
        <parameter name="retryCount" value="2"/>
    </test>
</suite>

Java

public class RetryAnalyzer implements IRetryAnalyzer {
    private int count = 0;
    private static final int MAX_RETRY = 2;

    @Override
    public boolean retry(ITestResult result) {
        return count++ < MAX_RETRY;
    }
}

// On test
@Test(retryAnalyzer = RetryAnalyzer.class)
public void myTest() { ... }

Flakiness Investigation Checklist

Symptom	Likely Cause
Fails on first run, passes on retry	Timing / race condition
Fails only in CI, passes locally	Environment / headless issue
Fails randomly, no pattern	Stale element or shared state
Fails after another test	Test order dependency
Fails on slow machines	Insufficient wait timeouts