The evolution of monitoring systems from basic infrastructure monitoring to advanced distributed tracing and observability solutions is driven by the need to understand complex software environments and address business challenges in digital-first organizations. Initially, software agents collected metrics and logs to diagnose issues, but as applications scaled, log analytics emerged as a centralized debugging tool. This gave rise to Application Performance Monitoring (APM) solutions, which evolved to include business metrics. Open source initiatives, led by major tech companies like Google, Twitter, and others, facilitated the development of standardized protocols and tools for distributed tracing, such as Zipkin, Jaeger, and Skywalking. OpenTracing and OpenCensus merged to form OpenTelemetry, aiming to provide comprehensive instrumentation standards. Despite the rapid expansion in open source options for observability, the field remains in flux, with ongoing efforts to improve maturity and integration across various systems.