This is the last lesson of K3. Nothing new gets built. The wrap-up has three parts: a ten-minute demo, a code walkthrough in which someone from your circle points at a spot and says “Explain this spot to me”, and practice questions about what you learned in K3. Nobody grades this; it’s your own check on whether the final project holds, together with the incident drill from 3.10.11. How much time you give it is up to you.

This lesson prepares you for all three parts. The most important thing first: nobody expects you to answer every question right away. What matters is that you know what you built, why, and how you find out what you don’t know.

The demo

Ten minutes is short. In ten minutes you can’t demonstrate a Kladde, only tell a story about it, and the best story of the final project is its goal: the Kladde runs from an empty subscription, monitored, recoverable, and you have proven it. A demo that follows this line:

Minute What you show Where from
0–1 What the Kladde is and for whom; the goals from 3.10.1 in one sentence docs/operations.md
1–3 The path of a change: a small pull request, CI green, deliver.yml up to dev a run you started before the demo
3–5 The overview and an alert that really arrived workbook, docs/alarm-probe.md
5–7 Teardown and rebuild: how long, and without a manual step docs/rebuild.md, rebuild-times.cs
7–8 The recovery: duration, rows, file docs/recovery.md, last run of restore-drill
8–9 The incident drill: cause and one action the postmortem from 3.10.11
9–10 What’s open, and one thing you would build differently today docs/wrap-up.md (exercise 2)

Three rules for the demo:

  • Evidence instead of claims. Every statement points to a run, a log, a query. “The rebuild takes an hour and fourteen minutes” is a statement; the table in docs/rebuild.md is the evidence.
  • At most one part live, and it’s prepared. Start the pull request for minutes 1 to 3 a quarter of an hour beforehand, so that deliver.yml has arrived in dev when you show it. Whatever fails live costs you your ten minutes; then show the run from the day before and say what you see. That’s operations too.
  • Nothing in prod during the demo. No approval, no drill, no rollback. A presentation is no reason for a change.

And practice once with a clock. Almost every first rehearsal of a demo takes twice as long as planned.