Multi-Account AWS Architecture for Regulated Workloads

Single-account AWS estates work until they hit a regulatory wall. The wall is usually a SOC 2 finding about access controls, a HIPAA inquiry about ePHI scope, or a PCI auditor asking how cardholder data is segmented from non-PCI workloads. Multi-account topology isn't optional at enterprise scale; it's the architecture that makes those questions answerable in days rather than months.

This whitepaper documents the multi-account topology we ship to enterprise clients: account-of-purpose taxonomy, transit-gateway hub-and-spoke network, AWS IAM Identity Center with JIT elevated access, policy-as-code with SCPs and Config rules, and the centralized audit pipeline that produces the evidence regulators actually pull from. With a documented migration path from single-account in three waves.