Add multilingual language and systems learning tracks

en/expanded-24-2/lesson-2/lesson.html

@@ -0,0 +1,6 @@
+<!doctype html><html lang="en"><meta charset="utf-8"><title>Observe latency, errors, and capacity</title><h1>Observe latency, errors, and capacity</h1><p>15-minute session: read for 3 minutes, trace for 3, experiment for 7, and complete the check for 2. Spend longer whenever you need.</p><p>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.</p><p><strong>Practice and evidence:</strong> 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.</p><pre><code class="language-python">from statistics import median
+samples_ms=[2,3,3,4,40]
+print(median(samples_ms))
+print(max(samples_ms))
+</code></pre><p><strong>Expected result:</strong> <code>3
+40</code></p><h3>Practice and evidence</h3><p>Keep three notes: your prediction, the actual result, and why they match or differ. The completion check grades understanding; the practice task builds skill.</p></html>