---
title: "Shadow deployment"
description: "A release stage in which a new model or system receives live inputs but its outputs are not used, so its behaviour on real traffic can be compared with the incumbent or with human decisions before…"
canonical: https://aigovernanceengineer.com/glossary/shadow-deployment
author: "Jorge García Aibar"
license: "CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)"
doi: https://doi.org/10.5281/zenodo.22956197
version: "0.5.0"
updated: 2026-09-25
---

# Shadow deployment

A release stage in which a new model or system receives live inputs but its outputs are not used, so its behaviour on real traffic can be compared with the incumbent or with human decisions before any exposure. The disagreement log is its evidence.

- Developed in: [ch. 15, Progressive delivery as a control](https://aigovernanceengineer.com/bok/governing-deployment#progressive-delivery-as-a-control); [ch. 05, Pattern: Staged Rollout with Rollback Criteria](https://aigovernanceengineer.com/patterns/staged-rollout-rollback-criteria)
- Chapters: [ch. 05, Patterns](https://aigovernanceengineer.com/bok/patterns) · [ch. 14, Development](https://aigovernanceengineer.com/bok/governing-development) · [ch. 15, Deployment](https://aigovernanceengineer.com/bok/governing-deployment)
- Contrast with: [Canary release](https://aigovernanceengineer.com/glossary/canary-release)
- In the glossary chapter: https://aigovernanceengineer.com/bok/glossary#t-shadow-deployment

## Sources

Defined by this Body of Knowledge: the section it is developed in is the source.