Definition
Category: Business | Level: Advanced
Service Level Indicators (SLIs) are quantitative measures of service performance; Service Level Objectives (SLOs) are target values for those indicators; Service Level Agreements (SLAs) are formal contracts guaranteeing those objectives to customers.
Why This Matters for Your Business
Without clear SLIs and SLOs, "the system is slow" is a matter of opinion. These metrics give your team objective data to prioritize engineering work, set realistic customer expectations, and make evidence-based decisions about when to invest in reliability versus new features.