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 deciding whether to maintain or sunset existing code. Replacing an old system, API, or library with a new one Sunsetting a feature that's no longer needed

Removing dead code that nobody owns but everybody depends on Reason: OldService requires manual scaling and lacks observability. Zombie code is code that nobody owns but everybody depends on. It's not actively maintained, has no clear owner, and accumulates security vulnerabilities and compatibility issues. Signs: | "Someone might need it later" | If it's needed later, it can be rebuilt. Keeping unused code "just in case" costs more than rebuilding. | | "We'll write the rollback if we need it" | A migration with no down path is a deploy you can't reverse. Write and run the down before merging. | Configuration keys: UPDATE, CREATE.

Run: npx -y skills add https://github.com/addyosmani/agent-skills --skill deprecation-and-migration --agent claude-code — the source lives at github.com/addyosmani/agent-skills.