database-schema-designer

# Database Schema Designer **Tier:** POWERFUL **Category:** Engineering **Domain:** Data Architecture / Backend --- ## Overview Design relational database schemas from requirements and generate migrations, TypeScript/Python types, seed data, RLS policies, and indexes. Handles multi-tenancy, soft deletes, audit trails, versioning, and polymorphic associations. ## Core Capabilities - **Schema design** — normalize requirements into tables, relationships, constraints - **Migration generation** — Drizzle, Prisma, TypeORM, Alembic - **Type generation** — TypeScript interfaces, Python dataclasses/Pydantic models - **RLS policies** — Row-Level Security for multi-tenant apps - **Index strategy** — composite indexes, partial indexes, covering indexes - **Seed data** — realistic test data generation - **ERD generation** — Mermaid diagram from schema --- ## When to Use - Designing a new feature that needs database tables - Reviewing a schema for performance or normalization issues - Adding multi-tenancy to an existing schema - Generating TypeScript types from a Prisma schema - Planning a schema migration for a breaking change --- ## Schema Design Process ### Step 1: Requirements → Entities Given requirements: > "Users can create projects. Each project has tasks. Tasks can have labels. Tasks can be assigned to users. We need a full audit trail." Extract entities: ``` User, Project, Task, Label, TaskLabel (junction), TaskAssignment, AuditLog ``` ### Step 2: Identify Re...