Who cares? There was recently a discussion on Trailblazer Gitter channel about Hashes as params, how to pass them around, and as customary a flame-war war ~~ensued~~ never happened, and it came down to a measuring contest: ~~whose~~ which key is better and faster.
Multi-tenancy is a hot topic these days. My definition of a multi-tenant application is a software system that serves multiple customers, each with their own isolated view of their own data in that system.
I’ve been teaching computer science and running schools for 14 years. Since 2012 I’ve created and run three developer training programs (Hungry Academy, gSchool/Galvanize, and Turing), running both the business and academics for each while training hundreds of happy alumni.