The Ezoic platform is able to automate the process of multivariate testing by acting as a proxy.
This is usually done by changing name servers at your registrar or - if you are a Cloudflare customer - by installing the Cloudflare app within your Ezoic dashboard:
How does it work?
When you add a site to the Ezoic system (by creating a new account here - or adding a site to your existing Ezoic account); the current DNS records are imported and replicated in your Ezoic dashboard. These include all your canonical values such as www., A records, and MX records for email, etc:
When a site is OFF in Ezoic, all of the requests are passed straight on to your host. You should keep the Ezoic system off while you're setting up Ad Tester:
When the system is turned on, the dashboard settings (set by you) directs traffic to testing and traffic to the original set up.
When a user visits a website, their browser calls for the content and is directed to the name servers for the site. Ezoic handles all these requests and directs the user to the IP address of the HTML - either pulling in Cached versions from a CDN or from your host.
All requests are called back to your original server using the IP address of your host and Ezoic then sends a user to an experimental page (which includes ad tester ads) OR serves the content in the normal way.
The DNS Settings at your registrar (or Cloudflare) are replicated in your Ezoic dashboard under Settings>DNS. Your website content IP doesn't change. All DNS records are replicated in Ezoic so that they keep to the same rules for site.
Ezoic creates Cloudfront DNS settings in the Ezoic DNS to ensure that all Ezoic sites get CDN support (caching content either with Cloudflare or Amazon's Cloudfront).
When the site is 'OFF' in the system - all requests continue to go to the same IP.