Scaling data processing from terabytes to petabytes is a technical challenge; doing it while strictly adhering to GDPR is an architectural one. In this session, I will share the evolution of our sovereign data platform, detailing how we transitioned from simple batch jobs to a complex, event-driven architecture that processes petabytes of data without leaving European soil. We will dive into the design of our "Compliance Car Wash", a mandatory ingestion pattern where every data stream is automatically scanned, masked, and anonymised by Argo Workflows before hitting persistent storage. Learn the hard-won lessons of scaling storage, optimising Argo for high throughput, and baking compliance directly into the infrastructure code, ensuring that as your data grows, your risk profile doesn't.