Glossary
End-to-end (E2E) testing verifies that an application works correctly from the user’s perspective by simulating real user flows through the full stack - UI, API, database, and third-party integrations.
Unit tests verify individual functions. Integration tests verify component interactions. E2E tests verify that the actual user journey works. A checkout flow might pass all unit tests but fail for real users because the Stripe iframe doesn’t load or the confirmation email doesn’t send. E2E catches what other test types miss.
Most teams use Playwright or Cypress to write E2E tests in JavaScript/TypeScript. Common pain points: long setup time (2–6 months for meaningful coverage), brittle CSS selectors that break on UI changes, and 60–70% of budget spent on maintenance rather than new coverage.
Zerocheck lets you write E2E tests in plain English. It interacts with your UI visually, runs approved tests on GitHub PRs, and records JSON evidence with screenshots, recordings, and step traces.