Amazon CloudFront, AWS WAF, and ALB

CloudFront is used as the entry point into the solution where the bid requests are received. CloudFront speeds up distribution of content through a worldwide network of data centers called edge locations. CloudFront ensures that end-user requests are served by the closest edge location. To prevent requests from bypassing the CDN and accessing the origin (ALB) directly, the solution uses CloudFront custom headers.

AWS WAF is a web application firewall that helps protect the application from common web exploits that could affect application availability, compromise security, or consume excessive resources. It is preconfigured with a set of standard AWS managed rules. AWS WAF is tightly integrated with CloudFront at the edge. Traffic can be received here as HTTP or HTTPS.

Note

If you want to opt out of using CloudFront and AWS WAF and directly send requests to the ALB, see How to opt out.