That new architecture design will typically let you scale your service to hundreds of thousands of users. The next logical step will be to look at how to improve performance and lower costs.

As mentioned previously, one of the most compelling reasons to use AWS is the amount of managed services that can be used in conjunction with your application. A lot of those services are geared toward very specific needs. For instance, if you do a lot of image transcoding, you may look into Elastic Transcoder or if you need reliable systems to send emails, you could look at Amazon Simple Email Service (SES), but some other services are more ubiquitous. In the previous section, we talked about adding more computing resources to handle more traffic. With our current model, we add more EC2 instances as the average CPU utilization gets higher and uses bigger instances, or adds more read replicas to the data tier. This solution is easy to implement and works great at first, but over time, becomes somewhat expensive. There are a number of ways in which we can easily improve the situation and make our application work smarter by reusing previously computed data through a caching layer. AWS has a service called ElastiCache that can come in handy in those situations.