Hi kumarm - Michael from AppLovin here. Thanks for the comment, it's an important concern. Here is a blog post outlining the problem and corrective actions that were taken: http://blog.applovin.com/applovin-security-notice/
How do you loadbalance requests between the servers?
We use a combination of software (ipvs, haproxy) and hardware load balancers. We plan on gradually moving away from traditional hardware load balancers.