Off the shelf Application Performance Monitoring (APM) tools often come with inherent drawbacks, such as steep costs, excessive data that exceeds human processing capacity, and incompatibility with open-source standards. While ingestion methodologies may adhere to open standards, data transmission, alerting mechanisms, and visualization features typically rely on proprietary systems. These issues, compounded by the 'Shannon Limit' of human cognition, result in an information overload from APM data, impeding effective decision-making.

OpenAPM counters these challenges with an innovative approach, offering a similar experience to standard APMs but leveraging open-source tools. Utilizing resources like OpenMetrics, PromQL, and Prometheus, all of which operate on open standards, OpenAPM facilitates greater control and flexibility over monitoring practices while maintaining vendor neutrality.

Deep-dive into the pillars of observability - Metrics, Events, Logs, and Traces (MELT) - coupled with an in-depth understanding of metric types, including Counters, Histograms, and Gauges, empowering developers to extract valuable system insights. Furthermore, developers can leverage the prom client libraries and packages to instrument their applications, enhancing their control over metrics monitoring.

Custom dashboarding using Grafana and PromQL paves the way for Minimum Viable Monitoring, focusing on critical metrics. Amid this technical context, observability evolves from being just a task to an iterative practice, crucial for managing system entropy. It encourages embracing the 'unknown unknowns' and navigating the inherent uncertainty in complex systems.