Load Testing

Load testing answers the question: what happens when many users access your application simultaneously? A feature that works perfectly for one user might slow to a crawl with a hundred concurrent users, or crash entirely under heavy load. Load testing reveals these breaking points before real users encounter them.

For vibecoded applications, load testing is important because AI-generated backend code often prioritizes functionality over efficiency. The generated database queries might work correctly but perform poorly at scale. The API endpoints might handle one request at a time but not implement proper connection pooling or caching for concurrent access.

While load testing is typically done with specialized tools like k6, Artillery, or Apache JMeter, the results often surface issues that need manual investigation. A load test might reveal that response times degrade, but a human tester is needed to determine the user impact and prioritize fixes. Combining load testing tools with human QA provides the most complete picture of application readiness.