Data Modeling

This skill designs the schema your product runs on, and gets multi-tenant isolation right — the mistake that, when wrong, leaks one customer's data to another.

Analogy: the schema is the foundation and load-bearing walls of a house. You can repaint and rearrange furniture later cheaply; moving a load-bearing wall after move-in is expensive and dangerous. Get the structure right before building on it.

Discovery (max 3 questions, only if unknown)

1. Is this multi-tenant (multiple orgs/customers sharing the app) or single-tenant?
2. Is the data mostly relational (users, orders, invoices) or document-like/flexible?
3. Are you on Supabase, Neon, or another Postgres host — or undecided?

Step 1 — Choose the database

Postgres by default — relational integrity, JSONB for flexible fields, full-text search, and it scales far. Don't reach for NoSQL without a proven document/scale reason. Every option below runs Postgres underneath, so the methodology in this skill (tenant_id + RLS, indexing, migrations) is identical regardless of host. Pick the host by how you're building: