How to Build a Tenant-Based Database in .NET Core (Step-by-Step Guide)

 Multi-tenancy is a foundational pattern in SaaS applications. In this guide, I’ll show you how to build a tenant-based (database-per-tenant) architecture using .NET Core and Entity Framework Core — step-by-step.

🧠 What is Tenant-Based (Database-per-Tenant) Architecture?

In a multi-tenant app, you serve multiple customers (tenants) from the same codebase. There are 3 main approaches:

Approach	Description	Use Case
Shared DB	One DB, with TenantId column	Simple apps
Schema-per-tenant	One DB, each tenant has its own schema	Medium complexity
Database-per-tenant	One DB per tenant	Maximum isolation & security ✅