Performance Testing Fundamentals

Summary

Verifying a system performs acceptably under expected (and unexpected) load — a distinct discipline from functional testing, focused on speed, stability, and scalability rather than correctness alone.

• 1Learn the key performance metrics: response time, throughput, and error rate.
• 2Understand why a functionally correct system can still fail under real-world load.
• 3Read about a real production incident caused by inadequate performance testing.