Customer-Facing vs Internal SLOs: When to Use Each

Customer SLOs are legal-adjacent; internal SLOs are diagnostic. Pick on audience; both have a place.

Customer-facing SLOs

Customer-facing: outcome (‘login works’); committed in contract or marketing.

Audience: external users; legal; sales conversations.

Internal SLOs

• Internal: process (‘auth-svc latency p99’); used by engineering teams.
• Audience: own team; platform team; on-call.

Cascade pattern

Customer SLO depends on multiple internal SLOs. Each internal SLO at 99.95% → customer SLO at 99.85% (math compounds).

Internal-tier breaches predict customer-tier breaches.

Ownership

Customer SLO owned by product/engineering jointly.

Internal SLOs owned by the team running the service.

Different owners; different decision rights.

Antipatterns

• Customer SLO without internal SLO support. Cannot diagnose breaches.
• Internal SLO never rolled up to customer view. Loses business context.
• One SLO type only. Missing half the picture.

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.