What Is APM (Application Performance Monitoring)?
APM — Application Performance Monitoring — is how teams see software the way users experience it: response times, error rates, throughput, and distributed traces that show exactly where a slow request spent its time. It's the top layer of the observability stack.
The Four Signals of APM
Latency
Response times per endpoint, percentile-by-percentile.
Errors
Failure rates, exceptions, and the stack traces behind them.
Throughput
Requests per second and saturation under load.
Traces
A request's full path across services, timed hop by hop.
The Trace Stops Where the Hardware Starts
APM is superb at answering "which service is slow?" It cannot answer "why is this host slow?" when the cause sits below the OS: a degraded RAID array stretching I/O, a thermal-throttled CPU, a flapping optical link on the storage path. The trace shows the database call taking 900ms; it can't show the failing disk behind it.
That's the hand-off point between APM and infrastructure operations. Sensaka isn't an APM tool — it's the layer underneath: hardware health, storage paths, network links, power, and thermal state, mapped to the services running on them. Paired with your APM, the 900ms trace ends at a named component instead of a shrug.
Common Questions About APM
What does APM stand for?
APM stands for Application Performance Monitoring (or Management) — tooling that tracks how applications perform for users: response times, error rates, throughput, and the traces that explain slow requests.
What is the difference between APM and infrastructure monitoring?
APM watches the application from the code down: transactions, traces, errors. Infrastructure monitoring watches from the hardware up: servers, network, storage, power. Full visibility needs both — most incidents get triaged in the gap between them.
What are APM tools?
Well-known APM tools include Datadog, Dynatrace, New Relic, and open-source options like Grafana with OpenTelemetry. They excel at application-layer visibility; the physical infrastructure beneath stays out of their scope.