Slo

Nines table with money attached; conversion via downtime cost; investment cost per nine; where each nine is earned; antipatterns (tyranny of the nines, MTBF without MTTR, redundancy without isolation); architectural choices that make availability cheap or expensive

Symptom → diagnosis → action playbook; three analytical lenses (Little's Law, utilisation curve, percentile arithmetic); capacity planning workflow; antipatterns (sizing for average, running at high utilisation, unbounded queues); when performance tuning doesn't apply