database-layer
Load PROACTIVELY when task involves database design, schemas, or data access. Use when user says \"set up the database\", \"create a schema\", \"add a migration\", \"write a query\", or \"set up Prisma\". Covers schema design and normalization, ORM setup (Prisma, Drizzle), migration workflows, connection pooling, query optimization, indexing strategies, seeding, and transaction patterns for PostgreSQL, MySQL, SQLite, and MongoDB.