handryos

# Building a Scalable Multi-Tenant SaaS with Sequelize and PostgreSQL Multi-Schema Architecture

## The Challenge: True Data Isolation in Multi-Tenant Applications

When building a SaaS application that serves multiple organizations (tenants), one of the most critical decisions is how to isolate tenant data. After months of development and facing real-world challenges, I want to share an architecture that solved a major problem I encountered with Sequelize in a multi-tenant environment.

## The Multi-Schema Approach

There are three main strategies for multi-tenancy:
1. **Shared database, shared schema** - All tenants in one table with a tenant_id column