Performance Impact Considerations

DAST performance impact on target applications varies with scan intensity. Aggressive scans sending thousands of requests per second can overwhelm applications, while conservative scans might miss time-sensitive vulnerabilities. Most DAST tools offer configurable scan speeds, allowing organizations to balance thoroughness with application stability. The external nature of DAST means performance impact is temporary and controllable.

IAST performance impact stems from continuous instrumentation overhead. Every request processed by an IAST-monitored application incurs some performance penalty from sensor execution. Modern IAST solutions minimize this overhead through optimized sensors, selective instrumentation, and efficient data collection. Typical overhead ranges from 5-15%, though this varies with application architecture and IAST configuration.

The performance trade-offs influence deployment strategies. DAST's temporary impact makes it suitable for production scanning during maintenance windows. IAST's continuous overhead typically limits production deployment to specific use cases. Most organizations deploy IAST in test and staging environments where performance impact is acceptable in exchange for comprehensive security coverage.