When you add end-to-end (E2E) testing to your React projects, you gain several powerful benefits. E2E tests provide confidence that your application works as intended from the user's perspective. By simulating real user interactions—such as clicking buttons, filling forms, and navigating between pages—these tests verify that the entire system, including frontend and backend, functions together correctly. This confidence helps you catch issues before they reach your users.

Another major benefit is preventing regressions. As your codebase evolves, E2E tests act as a safety net, alerting you when new changes accidentally break existing functionality. This means you can refactor or add features with less fear of introducing bugs. E2E testing also ensures your app works in real-world scenarios, covering user flows that unit or integration tests might miss.

However, E2E testing comes with its own set of challenges. One common issue is test flakiness—tests that sometimes fail for reasons unrelated to actual bugs. Flaky tests can erode trust in your test suite, making it harder to rely on test results. Maintenance overhead is another challenge: as your application changes, tests may need frequent updates to stay relevant and accurate. Additionally, E2E tests can be slower to run compared to other types of tests, which can impact developer productivity and feedback loops.