- Release management
Release candidate
A release candidate is a build that is functionally complete and considered ready for production, pending a final round of verification. Teams promote the same binary through staging, run smoke tests and acceptance checks against it, and either approve that exact artifact for release or reject it and produce a new candidate.
- Release management
Release train
A release train is a fixed, recurring release schedule: every change that is merged and passing by the departure time rides that release, and anything late waits for the next departure. It gives teams a predictable delivery cadence, usually weekly, biweekly or monthly, so shipping stops being a per-change negotiation and becomes a scheduled event on the calendar.
- Supply chain security
Reproducible build
A reproducible build always produces bit-for-bit identical outputs from the same source and inputs, no matter who runs it, when, or on which machine. It makes provenance verifiable: anyone can rebuild from source, compare hashes, and confirm the shipped artifact matches the claimed code.
- Release safety
Rollback
A rollback reverts a deployment to a previously known-good version when the new release misbehaves - restoring the prior artifact, container image, or routing target so users stop seeing the broken change. It is the safety net that makes frequent shipping possible: short, rehearsed, and ideally automated before it is ever needed in anger.
- Deployment strategies
Rolling deployment
A rolling deployment replaces old instances of an application with new ones a few at a time, so the service stays up throughout the change. Traffic shifts to healthy new instances as they come online while old ones drain - limiting downtime without provisioning the duplicate environment that blue-green requires.
- Operations
Runbook
A runbook is a written, step-by-step procedure engineers follow to run a system or handle a specific event - deploying a service, restarting a queue, rotating a secret, or recovering from an outage. Good runbooks are short, current, and often executable, so on-call responders can act quickly under pressure.