The way to think about scaling is simple: Every solution will be fine for a while, but will break at a different scale. The goal isn't to get something that s

The way to think about scaling is simple: Every solution will be fine for a while, but will break at a different scale. The goal isn't to get something that scales from the get-go, the goal is to make it so when you do need to scale you can do it without a ton of work. Building for millions of users is expensive, time-consuming, and difficult. If you're a startup with limited funding design for a small number of users first, because you won't get millions of users. Then as your user base ramps up start upgrading your pain points. If you do hit that millions-of-users mark immediately, hit up your backers for more money and throw hardware at it until you have time/space to rebuild your stack.