DeepL operates a complex multi-Region hybrid cloud network across AWS across Europe, North America, and Asia, integrating multiple Direct Connect locations with on-premises data centers. To perform maintenance without losing their closest-exit routing benefits, they combine AWS Cloud WAN and targeted BGP AS_PATH prepends, ensuring uninterrupted, localized traffic egress for unaffected regions.
- AWS Cloud WAN enables precise multi-Region traffic control during Direct Connect maintenance
- AS_PATH prepend redirects only affected Region traffic, preserving closest-exit routing elsewhere
- Trade-offs include some inter-Region data transfer while draining links
Infrastructure signal
DeepL’s network architecture spans multiple AWS Regions, with multiple VPCs and accounts per Region, linked to two European on-premises data centers via Direct Connect and MPLS-based fiber. The network is built with geographic redundancy and for low latency, routing outgoing traffic through the closest Direct Connect location by default.
Maintaining a single Direct Connect link requires traffic engineering that affects only that link’s region. AWS Cloud WAN’s integration with Direct Connect gateway allows DeepL to manipulate BGP attributes in the core network, avoiding disruptions for other regions. By leveraging local preference and AS_PATH prepends, the system shifts traffic off the link under maintenance while other Direct Connect locations handle their regions normally.
Developer impact
For developers and platform engineers, this approach reduces the risk of latency spikes and routing surprises during planned maintenance. The default closest-exit routing behavior remains intact for most workloads, preserving application performance across multi-region deployments.
This model demands a clear understanding of BGP routing order — specifically, how local preference dominates AS_PATH in AWS’s routing decision process. Developers working on network configuration or hybrid connectivity need tools and testing environments that replicate multi-Region routing with AWS Cloud WAN to validate traffic shifts before maintenance windows.
What teams should watch
Network and cloud platform teams should monitor for any increased inter-Region data transfer costs and latency impact while a Direct Connect link is drained. The trade-off for maintaining closest-exit routing during maintenance is that some traffic may traverse longer paths temporarily.
Operational teams should ensure accurate real-time observability into BGP path changes and verify that routing updates propagate as intended through the AWS Cloud WAN core. Integration testing focused on failover scenarios and core network edge routing behavior is critical to avoiding outages during link drains.