Multi Tenancy in Rails: The Decisions That Are Expensive to Reverse
Every SaaS makes a handful of decisions in its first month that it will live with for a decade, and most founders make them without noticing. This is a plain language walk through the ones that matter in a Rails product: how you separate one customer's data from another's, where the tenant lives in the code, who a user is when they belong to two companies, what a tenant is versus who pays the bill, and why the isolation model you pick is also your GDPR strategy. Written so a founder can follow the business consequence of each choice, with the honest cost of changing your mind later.







