New Relic probes integrated into Harness Chaos Engineering allow for objective validation of system performance against predefined Service Level Objectives (SLOs) during chaos experiments, offering metrics-driven resilience checks rather than subjective testing. By real-time querying New Relic metrics and comparing results against success criteria, teams can programmatically ensure systems maintain acceptable performance levels, even during induced failures, thus enabling automated reliability testing within CI/CD pipelines. This setup transforms chaos engineering into an automated, repeatable validation process by using probes to monitor application performance metrics continuously, helping to identify performance regressions before they reach production. The New Relic probe utilizes NRQL (New Relic Query Language) to target specific metrics, and users can define success criteria based on data type, comparison operator, and threshold values. This approach ensures that systems can handle adverse conditions by integrating probes into CI/CD pipelines, thus bolstering confidence in a system’s resilience and catching potential regressions early.