# Deprecation and Migration

> Sunset, migrate, and expand/contract without downtime

**Subcategory:** Workflow  
**License:** MIT  
**Source:** https://github.com/addyosmani/agent-skills/blob/main/skills/deprecation-and-migration/SKILL.md

---

## When it is useful

Manages deprecation and migration. Use when removing old systems, APIs, or features. Use when migrating users from one implementation to another. Use when migrating a database schema in production, such as renaming or dropping a column without downtime (expand/contract). Use when deciding whether to maintain or sunset existing code.

## The Catch

Expand/contract, then delete. Not a license to drop a column on Friday.