Deployment & Rollout Patterns for LLM Systems

Deploying LLM systems differs fundamentally from traditional software deployment. Model behavior is non-deterministic, prompt changes can cascade unpredictably, and quality regressions are harder to detect than functional bugs. This section covers battle-tested patterns for safely rolling out model updates, prompt changes, and new AI features to production.

Shadow Mode Deployment

Shadow mode (also called "dark launching") runs a new model or prompt version alongside the production system without exposing results to users. All requests are dual-written: the production path serves the user, while the shadow path processes the same input asynchronously for comparison.