SLO Policy Document: What to Write, What to Skip

An SLO policy that nobody reads is no policy. The minimum-viable shape is short and concrete.

Why a written policy

Without a policy, ‘the SLO’ is whatever the most-recent meeting said. Memory rots; numbers drift.

A short policy doc is the source of truth that survives manager turnover.

Four sections that matter

• 1. The SLO target with definition.
• 2. The error budget with consumption rules.
• 3. The action when missed (stop feature work? page exec?).
• 4. The review cadence.

Three to skip

Long history of past SLOs (use git). Architecture diagrams (use the design doc). Lessons learned (use postmortems).

The policy is a contract; not a wiki article.

Review cadence

Quarterly review: did we hit it? If not, what changed? Adjust target or invest in reliability.

Annual review: is this SLO still the right one? Customer expectations move.

Antipatterns

• SLO policy in one engineer’s head. Bus factor 1.
• 20-page policy. Nobody reads.
• Policy that does not say what to do when missed. Decoration.

What to do this week

Three moves. (1) Apply the pattern to your most-impactful service. (2) Measure adherence for 30 days. (3) Rewrite the policy or the SLO if the gap is durable.