Service Level Objective
A Service Level Objective (SLO) is a specific, measurable target for the reliability or performance of a service, typically expressed as a percentage over a time period (e.g., 99.9% availability per month). It is a key component of Site Reliability Engineering (SRE) practices, used to define the acceptable level of service quality for users. SLOs help teams make data-driven decisions about when to prioritize reliability improvements versus feature development.
Developers should learn and use SLOs when building and maintaining production services to ensure they meet user expectations and avoid reliability issues. They are crucial in SRE and DevOps contexts for setting clear reliability goals, guiding incident response, and balancing innovation with stability. For example, an e-commerce platform might set an SLO of 99.95% uptime to minimize revenue loss from downtime.