Service Levels — Overview#
Without this framework, system health is subjective. With it, every decision is backed by a number.
Metrics alone don't tell you if your system is doing well — you need targets, agreements, and consequences around those metrics. This folder covers the framework that turns raw measurements into actionable standards: SLI (what you measure), SLO (what you target), SLA (what you promise), and Error Budget (how much failure you can afford).
Files in this folder#
| File | Topic |
|---|---|
| 01-Introduction.md | Why this framework exists, how it differs from just using percentiles |
| 02-SLI.md | Service Level Indicator — the actual measurement your system produces |
| 03-SLO.md | Service Level Objective — the internal target for that measurement |
| 04-SLA.md | Service Level Agreement — the external contract with consequences |
| 05-Error-Budget.md | How much failure is allowed, and how it drives deployment decisions |
| 06-Interview-Cheatsheet.md | How to use SLI/SLO/SLA in a design interview |