What should I check for slow APIs, memory growth or intermittent 500s?
Try code in the playgroundUnderstand the concept
Slow responses, growing memory and 500 errors are symptoms, not root causes. A useful investigation connects each symptom to a specific route, instance, input or dependency. Comparing healthy and unhealthy requests often narrows the problem faster than changing settings blindly.
Important ideas
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Slow API: separate app time, pool wait, DB time and external API time.
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Memory growth: compare heap snapshots; inspect caches, listeners and large payloads.
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500s: group errors by route, app instance and deployment; use request IDs to trace failures.
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Check release timing and resource saturation, but keep multiple hypotheses until measurements distinguish them.
Can you explain it without the notes?
What should I check for slow APIs, memory growth or intermittent 500s?
Use your own words. Explain an example and one limitation before checking the explanation.
Check your explanation
Slow responses, growing memory and 500 errors are symptoms, not root causes. A useful investigation connects each symptom to a specific route, instance, input or dependency. Comparing healthy and unhealthy requests often narrows the problem faster than changing settings blindly.
Turn this concept into a clear answer.
- State what evidence would confirm or reject your first hypothesis, then verify the fix with the same measurement.
Keep connecting the ideas.
Next lesson: What if the event loop, DB pool or third-party API is stuck?Adapted from 02_NODE_EXPRESS_HTTP.md · “What should I check for slow APIs, memory growth or intermittent 500s?”. Examples are study fragments; framework behavior can depend on your version.