Designing Data Models for a Multi-Business SaaS

Multi-tenant software — where each customer runs their own books inside your system — demands careful data modeling.

Isolating tenants

Every business is a tenant whose data must stay separate. Model tenant identity on most collections so you can scope every query correctly.

Products and inventory

Businesses hold products with stock, purchase, and sales history. Link transactions to products while keeping totals queryable for reporting.

Ledgers and money

Financial data needs an audit trail. Prefer immutable transaction records over mutable balances, and derive account totals from the ledger.

Permissions and users

Map users to roles per tenant so staff see only their organisation's data and actions.

Wrapping up

A well-isolated, auditable model is what lets one codebase safely power many independent businesses.