# Continuous Deployment

## Definition
Continuous Deployment (CD) is a DevOps practice where code changes that pass all automated tests are automatically deployed to production environments without manual intervention.

## Key Characteristics

### Across DevOps Maturity Levels
| Maturity | CD Practice Level |
|----------|-------------------|
| Phase 1 | Manual deployments, milestone-based releases, no automation |
| Phase 2 | Automation used to reduce release risks, but still requires manual triggers |
| Phase 3 | Automated infrastructure provisioning, more frequent deployments possible |
| Phase 4 | Continuous integration pipeline enables tangible business benefits; infrastructure and code managed through pipelines |
| Phase 5 | Multiple deployments per day with high certainty and minimal risk; zero human intervention for code changes passing through the pipeline |

### Core CD Elements
- Automated deployment pipelines
- Zero human intervention after code commit
- High confidence in automation quality
- Fast rollback capabilities
- Progressive delivery strategies (canary, blue-green)
- Real-time monitoring post-deployment

## Relationship with Continuous Integration

CD builds on CI. The full CI/CD pipeline:
1. **CI** — Every code change triggers automated builds and tests
2. **CD** — Changes passing CI are automatically deployed

At Phase 5 maturity, the CI/CD pipeline achieves **continuous deployment** where code flows from commit to production automatically.

## Business Impact
- Faster time-to-market
- Reduced release risk through smaller, incremental changes
- Rapid feedback from production users
- Higher team productivity
- Competitive advantage through rapid iteration

## Sources
- [[sources/devops-maturity-model-from-traditional-it-to-advanced-devops.md]]
- [[sources/cloud-devop-maturity-guideline.md]]

## Related Concepts
- [[concepts/CI-CD-Pipeline]]
- [[concepts/Continuous-Integration]]
- [[concepts/DevOps-Maturity]]
- [[concepts/Infrastructure-as-Code]]
- [[concepts/Error-Budget]]