Paths/DevOps Engineer/Incident Response / Postmortems & Runbooks
Write the Postmortem
The service is back. The part everyone skips is the write-up. Produce a postmortem with impact, root cause and action items - the three sections every blameless review requires.
Validator
IDLE — checks run live as you type commands; submit when done
01Requirements
live checks- File ~/incident/postmortem.md exists○
- The postmortem states the impact○
- The postmortem states the root cause○
- The postmortem lists action items○
- The postmortem names the root cause of the api outage○
02Walkthrough
6 steps- 01
Create the incident folder
The postmortem lives next to the evidence it is based on.
mkdir ~/incident - 02
Write the impact
Start with the user-visible effect and the duration. Numbers beat adjectives.
echo 'Impact: api was unavailable for 42 minutes after the 09:12 deploy' > ~/incident/postmortem.md - 03
Add the root cause
Name the technical cause, not the person who shipped it. Blameless means the system allowed the mistake, not that nobody made one.
echo 'Root cause: the api Deployment was missing the DB_HOST environment variable' >> ~/incident/postmortem.md - 04
Add the action items
Every action item needs an owner and a deadline. 'Someone should add a health check' is a wish, not an action item.
echo 'Action items: fail fast when DB_HOST is missing - owner platform, due Friday' >> ~/incident/postmortem.md - 05
Read it back
cat prints the whole postmortem. Read it as if you were the person asking why.
cat ~/incident/postmortem.md - 06
Submit for validation
The validator checks the three required sections and the root cause.
03Stuck?
0 of 3 revealedTake a hint without losing the lab — each one points at the thing to look at, not at the answer.
04AI Tutor
guides, never solvesTell me what you're stuck on — I'll nudge, not solve. Which requirement are you looking at?
04Notebook
saved locally in this browserlearner@lab — ubuntu:24.04
Session is disposable
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