# A/B + Shadow Traffic: Feature Flag + Canary 1%→5%→25% + Automated Rollback

> Source: https://sukruyusufkaya.com/en/learn/fine-tuning-cookbook/ftc-ab-shadow-canary-rollback
> Updated: 2026-05-14T14:43:01.828Z
> Category: Fine-Tuning Cookbook (Model-by-Model)
> Module: Part XVI — Production Operations
**TLDR:** Safe way to put new FT model in production: shadow traffic (old + new in parallel, compare responses), canary deployment (gradual rampup 1%→5%→25%→100%), feature flag (LaunchDarkly / GrowthBook / Unleash), automated rollback (P95 latency or error rate threshold).