Meaning
Service Level Objective; an internal performance goal that an engineering team aims to achieve to keep systems reliable before breaching SLAs.
Three examples from work
Reliability engineering
SREOur internal SLO is 99.95% availability, even though our external SLA is only 99.9%.
LeadThat buffer gives us time to fix emerging problems before incurring contractual penalties.
Feature freeze discussion
LeadIf we burn through our error budget and violate our SLO, all new feature work freezes.
POThen let's prioritize test automation and resilience this sprint.
Latency monitoring
DevOur search endpoint is meeting its latency SLO of p95 under 300ms.
LeadGood, keeping latency low protects user engagement.
Pronounce each letter: 'S-L-O'. Teams use error budgets derived from SLOs to balance new feature velocity against stability.