What are the technical challenges of successfully DDoS-ing a Rainbow Six Siege server?

Successfully DDoS-ing a Rainbow Six Siege server is extremely difficult. Ubisoft employs robust DDoS mitigation techniques, including traffic filtering, rate limiting, and content delivery networks (CDNs). Modern game servers are also designed to withstand such attacks. Attackers would need to generate a massive volume of traffic from a distributed network of compromised devices, while simultaneously evading detection and mitigation systems. The scale of resources required makes a successful attack improbable.