deprecation-and-migration
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).
- Kind
- Skill
- Works with
- Claude Code, Codex, Any agent
- Source
- addyosmani/agent-skills @ 2686b620fc1f
- Path
- skills/deprecation-and-migration/SKILL.md
- License
- MIT
- Jobs
- Implementation
InstallCopy it from the source repository, or sign in and let the assistant adapt it for your project.
# Deprecation and Migration ## Overview Code is a liability, not an asset. Every line of code has ongoing maintenance cost — bugs to fix, dependencies to update, security patches to apply, and new engineers to onboard. Deprecation is the discipline of removing code that no longer earns its keep, and migration is the process of moving users safely from the old to the new. Most engineering organizations are good at building things. Few are good at removing them. This skill addresses that gap. ## When to Use - Replacing an old system, API, or library with a new one - Sunsetting a feature that's no longer needed - Consolidating duplicate implementations - Removing dead code that nobody owns but everybody depends on - Planning the lifecycle of a new system (deprecation planning starts at design time) - Deciding whether to maintain a legacy system or invest in migration ## Core Principles ### Code Is a Liability …