APM
Application Performance Monitoring: tools that track request latency, error rates, and dependencies in real time. Datadog, New Relic, and Grafana are popular APM platforms.
What is APM?
Application Performance Monitoring: tools that track request latency, error rates, and dependencies in real time. Datadog, New Relic, and Grafana are popular APM platforms.
APM is a intermediate-level concept that sits in the Observability & Monitoring area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "APM" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
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Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
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Lessons that touch on APM as part of a larger topic.
See also
Related glossary terms you might want to look up next.
Distributed Tracing
Tracking a request as it flows through multiple services in a distributed system. Each service adds its trace, creating a full picture of the request journey.
Metrics
Numerical measurements collected over time that describe system behavior: request rate, error rate, latency percentiles, CPU utilization. Prometheus is the standard collector.
Observability
The ability to understand a system's internal state from its external outputs. Built on three pillars: metrics, logs, and traces.