migration▌

Safe database schema evolution for production apps with user data. Core principle Migrations are immutable after shipping. Make them additive, idempotent, and thoroughly tested.

SwiftData (Before)

SwiftData schema migrations move your data safely when models change. Core principle SwiftData's willMigrate sees only OLD models, didMigrate sees only NEW models—you can never access both simultaneously. This limitation shapes all migration strategies.

Master AngularJS to Angular migration, including hybrid apps, component conversion, dependency injection changes, and routing migration.

Systematically convert Android XML layouts to idiomatic Jetpack Compose, preserving functionality while embracing Compose patterns. This skill covers layout mapping, state migration, and incremental adoption strategies.

Implement robust database migration systems with version control, rollback capabilities, and data transformation strategies. Includes migration frameworks and production deployment patterns.

One-shot migration from Sonnet 4.0, Sonnet 4.5, or Opus 4.1 to Opus 4.5.

Comprehensive migration guide for converting Create React App projects to Next.js, covering routing, data fetching, components, styling, and deployment. Contains 148 rules across 17 categories, prioritized by migration impact. After a successful migration the application should work the same as it did before the migration.

Orchestrator-only workflow for migrating or rewriting codebases. You do NOT read files, write code, or validate anything yourself. You only instruct agents and pipe context (paths, not contents).

Master database schema and data migrations across ORMs (Sequelize, TypeORM, Prisma), including rollback strategies and zero-downtime deployments.