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, su
What it does
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.
Quality judgment
Comprehensive coverage of deprecation decisions, migration patterns (strangler, adapter, feature flags, expand/contract), zombie code, rationalizations, red flags, and verification checklists, with concrete code and worked examples. The description's triggers align tightly with the content, including the database schema migration case. Only minor gaps (e.g., communication cadence/timelines for compulsory deprecation) keep it from a perfect 10.