Quiz: Postmortems & SLOs

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3 questions

L1 (2 questions)

1. What is an error budget, and what should happen when it is exhausted?

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Error budget equals 1 minus the SLO. For a 99.9% SLO, the error budget is 0.1%, which equals 43.2 minutes per 30-day window. When the budget is exhausted, the error budget policy kicks in: typically a feature freeze until the budget recovers, all engineering effort on reliability, and mandatory postmortems for budget-depleting incidents.

2. In a blameless postmortem, what does 'blameless' actually mean? Does it mean no one is accountable?

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Blameless does NOT mean accountable-less. It means focusing on systems and processes rather than individuals. Instead of 'John pushed bad code,' write 'the deploy pipeline lacked a canary step.' Instead of 'the on-call should have known,' write 'the runbook was outdated.' The goal is organizational learning. Individuals are not punished for following the process — the process is fixed instead.

L2 (1 questions)

1. What makes an SLI 'good' versus 'bad'? Give an example of each.

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Good SLIs measure what users experience. Bad SLIs measure internal infrastructure metrics. Good: percentage of successful HTTP requests (availability), p99 response time (latency). Bad: CPU utilization (does not reflect user experience), average response time (hides tail latency), test pass rate (internal metric). SLIs should map to user-visible quality.