How Did Dnsimple Replace a User-equals-account Login With a Many-to-many Relationship So One User Can Reach Many Accounts?

DNSimple bound each user to an account at the start. Login credentials were tied to billing and access control. Over the years the binding blocked new work, so DNSimple decoupled users from accounts into a many-to-many relationship. Many users can now belong to many accounts.

People use DNSimple for personal domains. The founder has domain names and also works on DNSimple domain names. DNSimple segments domains for set reasons: production domains sit in one highly restricted account, and other domains are experiments for fun. The founder says DNSimple might build a site or run something off an experimental domain without knowing whether it will live. A single user reaches each account under different access control. When a user was an account, separate access was impossible. The bigger application code gets, or the longer it lives, the harder a fundamental design decision becomes to change.

A business that must race toward the next round of funding, the next round of debt, a public listing, or the next revenue target will build around a core system instead of updating it. DNSimple never raised any funds, is profitable, and chose to change the core user-and-account relationship while still servicing customers.