Terms beginning with Z cover seamless releases and resilience — zero-downtime deployments, availability zones and zombie processes. Each entry is a short, citable definition.
Zero-downtime deployment ships a new version of a running service without dropping user requests or scheduling an outage window. It combines patterns like rolling updates, blue-green swaps or canary shifts with readiness checks and graceful shutdown, so old instances keep serving traffic until the new ones are proven healthy and ready to take over.