Beyond Status Codes: Detecting Hidden API Failures with Statistical Analysis

Traditional uptime monitoring misses critical failures hidden behind 200 OK responses—such as cached errors, degraded latency, or missing data. This article demonstrates how simple statistical methods using rolling averages and three-sigma thresholds can reliably detect these anomalies without machine learning, offering superior explainability and cost efficiency. It exemplifies a broader trend where domain-specific, deterministic approaches often outperform AI-driven solutions for focused technical problems.