This Video provide the techniques that allow you to make your App Scalable from Day 0. It also tells about how you can set a basic architecture that can grow as your users grow using amazon web services. When you got a lot more traffic and then you came to know that your App is not scalable. At that time it Is a lot more difficult to make your App scalable. So, why not follow a standard technique that can save you cost, time and efforts.
Use of cloud services like Amazon AWS can help you setup the backend of your apps or websites in a way that you can scale easily as your users grow without incurring huge costs on redesign of architecture or hosting costs.