What is the primary purpose of end-to-end testing?

• A. Validate an entire user workflow across multiple services.
• B. Test a single function in isolation.
• C. Verify deployment scripts.
• D. Measure system CPU utilization.

Answer: (A)

End-to-end testing focuses on validating the complete user journey across all integrated components. It exercises a full workflow—from the user interface through APIs, services, and data stores—often including external systems, to ensure data flows correctly and the system behaves as a real user would expect. This broad scope captures how different parts interact, catches integration issues, and verifies that the end-to-end experience works as intended, not just that individual pieces function in isolation. That makes it the best fit for validating an entire user workflow across multiple services. Other approaches target narrower goals: testing a single function in isolation is unit testing, which checks individual components; verifying deployment scripts relates to deployment/infrastructure checks; and measuring CPU utilization focuses on performance, not the whole workflow.