Web traffic routing

Hi, There's an online service that does fraud detection by forwarding web traffic to their platform before sending it to its destination. They claim they do it by one of two methods: 1) Traffic is routed to our Cloud via DNS for dynamic async or sync processing before being proxied to the customer’s website or API. 2) Traffic is mirrored or routed to our ] Cloud via serverless functions in Cloudflare, Fastly, Akamai, or AWS. Routed traffic is proxied to our customer’s website or API. If anyone can point me to how these two work, i'd appreciate it. Also, any potential issues related to performance. Thanks, Sam