Public IT incident case studies / Vol. 01
Root Cause Casebook is a field guide to how technology teams diagnose public IT incidents. Each evidence-grounded case preserves the hypotheses, wrong turns, decisive tests, and reasoning that narrowed the fault domain.
Study the latest caseApplications · Complexity 5/10
ThousandEyes examined a broad Meta outage affecting Facebook, Messenger, WhatsApp, and later Instagram. The most valuable reasoning move was showing that frontend network reachability remained normal while application errors and timeouts rose, which excluded one major fault domain immediately.
How to investigate an IT incident
Record what users and systems actually reported.
Keep the first plausible explanation provisional.
Find observations that narrow the fault domain.
Identify what changed the investigation’s direction.
Name the mechanism that survived the evidence.
Previous investigations