2 — Severity Classification

Site Reliability Engineering: From Foundations to Internet-Scale Systems

The complete 184-chapter, 15-part Site Reliability Engineering curriculum — from Linux internals and distributed-systems theory through reliability engineering, observability, incident response, platform engineering, and Staff/Principal-level MAANG interview preparation, ordered the way SRE expertise actually develops rather than as a topic index.

6 — Runbooks

Step-by-step operational procedures written before the incident, so 3am execution doesn't depend on anyone's memory of how a system behaves under stress.

7 — Playbooks

Decision trees for ambiguous or novel incidents, one level up from a runbook's fixed steps — how to reason through a failure mode nobody's documented yet.

8 — Root Cause Analysis

Moving past 'a bad deploy caused it' to the systemic condition that let a bad deploy reach production undetected in the first place.

9 — Five Whys

The simplest RCA technique that works — repeatedly asking why until you hit a structural cause — and where it breaks down on genuinely multi-causal incidents.