• Release management

  Dark launch

  A dark launch ships new code to production but keeps the change hidden from users. The code runs in the live environment - often exercised by silent backend calls or an internal cohort - so teams can measure performance, correctness and capacity under real production traffic before ever exposing the feature to customers.

• Delivery metrics

  Deployment frequency

  Deployment frequency is how often a team successfully releases changes to production. One of the four DORA metrics, it gauges delivery speed and the maturity of a team's CI/CD practice: elite performers ship on demand, multiple times per day, while low performers manage less than one production deploy per month.

• Observability practices

  Deployment marker

  A deployment marker is a timestamped annotation posted to a monitoring, logging or APM system every time a new version ships, so charts, alerts and incident reviews can visually correlate a metric change with the exact release that caused it. Most pipelines emit it as a small HTTP call right after a successful deploy.

• Deployment strategies

  Deployment ring

  A deployment ring is a release strategy that ships a new version to progressively wider, named cohorts of users - typically an internal ring first, then a beta ring, then general availability - promoting between rings only after each cohort's health signals stay clean, so problems surface in a small audience before reaching everyone.

• Release management

  Deployment window

  A deployment window is a scheduled span of time during which changes are allowed to reach production. Teams use it to concentrate risky releases into hours when experts are on hand, avoid peak traffic and change freezes, and give operations, support and customers a predictable, communicated cadence for updates.

• Delivery metrics

  DORA metrics

  DORA metrics are four research-backed measures of software delivery performance: deployment frequency, lead time for changes, change failure rate, and mean time to restore service. Together they describe how fast a team ships and how reliable those changes are, making delivery health concrete instead of based on opinion.