At the beginning of the world there was a Rails app, built to solve a specific problem and it happens to be a single tenant app. In another SAAS world, with a freemium model, most of the tenants that signs up (after finding you on Google) are 'kinda lazy’, and don’t really use the app, and don't do anything other than signup. There will be, however, a few special users out there waiting for your app. They also found you on Google, signs up, logins on a daily basis, use it, and use it. Importantly, these special users had allocated the same amount of resources as the ‘kinda lazy’ ones.
To scale in the scenario describe requires a change in approach: Special tenants get Special treatment, while ‘kinda lazy’ tenants get default treatment (and shared resources).
In this talk I will describe a few options that are available for this problem.