Multi-Tenancy: Serving Many Customers from One Codebase

Multi-tenancy lets a single SaaS platform serve dozens or hundreds of customers with full data isolation. Two common approaches exist: a separate database per tenant, or a single database with discriminator columns (tenant_id). The choice depends on isolation, compliance, and data-volume requirements. Tools like stancl/tenancy in Laravel simplify per-tenant connections and migrations, but real success comes from clear boundary design and careful performance monitoring from day one.