Multi-Tenancy in SaaS: The Architecture Decision You Can't Undo Later Most early architecture decisions in a SaaS product are reversible. Wrong framework? Migrate it. Wrong hosting provider? Move it. Wrong multi-tenancy model? That one's expensive to fix once you have real customers and real data sitting in production. If you're building a SaaS platform and haven't explicitly decided how tenant data is isolated, you've actually already made the decision by default — usually the one that's...