Observe latency, errors, and capacity

15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.

Averages hide slow requests. Record a latency distribution, error count, resource use, and the measurement window. Avoid logging passwords or private payloads. The sample computes a median from fixed demonstration data; it is not a measurement of the server. Replace the data with a bounded local experiment and label its environment.

Practice and evidence: Predict the example or draw its state transitions. Change one assumption, test the boundary, and record the actual result. Explain what this small model does not establish about a production system.

from statistics import median
samples_ms=[2,3,3,4,40]
print(median(samples_ms))
print(max(samples_ms))

Expected result: 3 40

Practice and evidence

Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.