Headless & parallel — speed

Headless Chrome + the DriverFactory

Headless Chrome is the same browser without a window — needed for CI, faster everywhere. This finishes the DriverFactory promised in the framework lesson, honoring the -Dheadless=true flag your workflow already passes:

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.*;

public class DriverFactory {
    public static WebDriver create() {
        ChromeOptions options = new ChromeOptions();
        if (Boolean.parseBoolean(ConfigReader.get("headless"))) {
            options.addArguments("--headless=new");        // modern headless mode
            options.addArguments("--window-size=1920,1080"); // or responsive layouts differ!
        }
        return new ChromeDriver(options);
    }
}

// BaseTest setUp() becomes one line:
//   driver = DriverFactory.create();

mvn test "-Dheadless=true"

[INFO] Tests run: 14, Failures: 0, Errors: 0, Skipped: 0
[INFO] Total time:  01:57 min        ← was 03:10 with windows drawn

Parallel: JUnit does it natively

One properties file turns it on — no pom changes:

junit.jupiter.execution.parallel.enabled=true
junit.jupiter.execution.parallel.mode.default=same_thread
junit.jupiter.execution.parallel.mode.classes.default=concurrent

[INFO] Tests run: 14, Failures: 0, Errors: 0, Skipped: 0
[INFO] Total time:  38.4 s           ← classes ran side by side

The chosen mode — classes in parallel, methods within a class sequential — is the safe default for UI suites: each class's tests share nothing, and each test still gets its own browser from @BeforeEach.

The catch that separates juniors from seniors

Parallel tests must be independent: no shared static driver, no test relying on another's leftovers, no two tests editing the same user's data. Every discipline this course insisted on — fresh browser per test, no ordering, API-created test data — was quietly preparing your suite to parallelize safely. If a suite fails only in parallel, one of those rules is being broken somewhere; that diagnosis skill is interview gold.