Linux & Site Reliability Foundations

Real portfolio pieces built during the course, not a certificate for its own sake. Each one is work you can show.

• Monitoring dashboard specA one screen dashboard specified panel by panel: the service level indicator and budget on the top row, the four golden signals below it, the dependencies that explain them, and a written note of what you deliberately left off and why.
• On call runbookA runbook for the database timeout alert, written for a tired stranger: what it means in user terms, five read only checks with expected values, what to capture before mitigating, when to escalate, and the do not list.
• Automation scriptA disk pressure triage script that is read only by default, checks its assumptions and refuses clearly when they do not hold, is safe to run twice, and hands the destructive options back to a human.
• Blameless postmortemA write up of the 3am incident with impact in user terms, a timeline built from captured evidence, contributing factors that name mechanisms rather than people, what went well, where you got lucky, and actions with owners and dates.
• SLO and error budgetOne page defining the indicator as a ratio of good events to valid events, the exclusions and why each is fair, the target with the four inputs behind it, the budget arithmetic, two burn rate alerts and the agreed policy for an exhausted budget.
• Alert reviewEvery alert that woke somebody this week, reviewed the way you would diagnose a service: what it actually measures against what it is trying to protect, its own firing history with the actions recorded beside it, a verdict of rewrite, delete or keep with what settled it, the replacement written out as an expression rather than as a philosophy, and the detection gap the change creates stated out loud rather than glossed over.
• Change plan with a rollbackOne risky change planned so that its cost lands where it does not matter: the window and why that window, the steps in the order they happen with what has to be true before each one starts, what it costs while it runs and out of whose budget, the number that stops the work with the person who can call it, and the rollback written before anything is touched. Including an honest answer to whether it should happen at all this week.