If you make use of your own CDN such as Akamai or Cloudflare, it's possible to use it in front of the newsroom.
For HTML content, we use caching in our application server. To prevent running into cache invalidation issues or having changes to the text of articles not being immediately visible, it's recommended to lower the TTL or Max-Age for caching or set it to 0.
This makes sure that you still have the DDOS protection that your CDN affords you without running into caching issues.
To serve non-HTML assets we use Amazon Cloudfront. These are served from the domain content.presspage.com and will not go via your CDN.
If you use your own CDN such as Akamai or Cloudflare make sure that requests with query string parameters do not get filtered out, but get forwarded to the origin instead. If this doesn't happen, it may cause issues with the Search, Download and Headline Modules.