Glossary term
What is Headroom? Meaning for developers
Spare capacity for spikes and failures. Example: Running servers at 60% CPU, not 95%.
Learn it properly · System DesignLesson 8: Latency, Throughput & Why p99 MattersAn 80 ms average can hide a checkout that freezes for five seconds. Latency, throughput and Little's Law, why queues explode near full utilisation, and why at scale the p99 becomes what most users feel.