In this chapter, we will introduce key design principles and approaches to achieving scalability in applications deployed on the AWS cloud. As an enterprise or a start-up at its inflection point, you never want your customers to be greeted with a 503 message (that is, Temporarily Unavailable). The approaches in this chapter will ensure your web and mobile applications scale effectively to meet your demand patterns, growth in business, and spikes in traffic. We will also show you how to set up auto scaling in order to automate the scalability in the sample application.

In this chapter, you shall learn about:

• Defining scalability objectives
• Designing scalable application architectures
• Leveraging AWS infrastructure services for scalability
• Setting up auto scaling for your deployed application