Sinatra for the API, Redis & PostgreSQL for data, Ember & SCSS on the front-end. Redis should be able to handle the most common data for 10k users, with PG for

Sinatra for the API, Redis & PostgreSQL for data, Ember & SCSS on the front-end. Redis should be able to handle the most common data for 10k users, with PG for the less commonly requested data. No particular reason for choosing Ember other than I like it better than Angular/Knockout/Backbone, and same for SCSS as opposed to LESS/Stylus. I feel like Node would be overkill in this scenario, Sinatra is so much faster to develop with (for me personally, I'm sure there are plenty of Noders out there who could swing it with their eyes closed). PostgreSQL + Redis + Ember + SCSS + Sinatra; I call it "The PRESS Stack"