Java: Unit Testing with JUnit

It ensures consistent and scalable testing.

Automated testing is essential in large projects as it consistently checks that code changes don't break existing functionality, which is key to maintaining a stable application. Automated tests run faster and more reliably than manual tests, allowing teams to focus on development rather than repetitive testing tasks. In a large e-commerce project, automated tests can quickly verify that new features like promotions or discount codes don't disrupt the checkout process.