We are expanding our SaaS platform to Europe and Asia, and we need to comply with strict GDPR and local data sovereignty laws. How are you all using AWS cloud technology to ensure user data stays within specific geographic boundaries while still maintaining a global user experience? Should we go for a completely decentralized architecture, or is there a way to use Global Accelerator with localized RDS instances?
3 answers
Data residency is one of the trickiest parts of global scaling. The most common pattern I’ve seen is the "Regional Silo" approach, where you deploy a full stack in each required region (e.g., eu-central-1 for Germany). You can use Amazon Route 53 with Geolocation routing to point users to the correct stack. In 2024, AWS Control Tower has become essential for this; it allows you to set "guardrails" that physically prevent developers from creating resources or moving data into regions that aren't approved for a specific project's compliance level.
How do you plan on handling the "global" part of the user profile? If a user travels from London to New York, does their data stay in Europe, or do you have a mechanism to migrate the record to a US shard?
You might want to look into AWS Outposts if the residency requirements are so strict that the data cannot even leave a specific physical building or country that doesn't have an AWS region.
Outposts are a great suggestion for those edge cases. We used them for a client in a country with no local AWS presence, and it worked flawlessly for staying compliant.
Daniel, that's the million-dollar question! Currently, we keep the "home" region as the source of truth to comply with the initial data collection consent. If they travel, they experience a slight latency hit as the US front-end queries the EU database. We’ve looked into "Global Tables" for DynamoDB, but the automatic replication actually violates some of our stricter residency requirements, so we have to be very careful about which attributes we sync globally versus what stays local.