IaaS sub-processors are the third-party providers your primary Infrastructure-as-a-Service vendor relies on to deliver compute, storage, networking, and security. They operate below the surface, but their actions can affect data integrity, performance, and compliance. Understanding them is not optional.
Every major IaaS provider—AWS, Azure, GCP—maintains a supply chain of specialized services. These sub-processors handle tasks like data replication across regions, DDoS mitigation, backup orchestration, or hardware maintenance. Some work on physical infrastructure; others run in software layers. If one of them fails or changes policy, the consequences hit your workloads directly.
Compliance frameworks such as GDPR, HIPAA, and SOC 2 require visibility into all entities that process or store regulated data. A sub-processor is subject to these rules even if you never interact with them. If your IaaS uses a CDN provider to deliver traffic, that CDN is processing data. If your cloud vendor contracts out disk disposal, they are processing data. Every link in the chain matters.