An Australian ecommerce company hosts services in ap-southeast-2 with multiple VPCs attached to a transit gateway and plans to replicate the architecture to us-west-1. The company wants connectivity between applications in the two Regions that maximizes bandwidth, minimizes latency, and reduces operational overhead. Which solution meets these goals?

Transit Gateway peering is the most suitable solution. It allows direct, high-bandwidth, low-latency connectivity between Transit Gateways in different AWS Regions. This minimizes operational overhead by centralizing routing and avoiding the need for multiple VPN connections or complex routing configurations. You would then configure static or dynamic routes on each Transit Gateway to direct traffic to the appropriate IP ranges in the peered Region. VPN attachments between Transit Gateways would work but introduce higher latency and lower bandwidth compared to direct peering. Deploying VPN servers in VPCs adds significant operational overhead, requires managing instances, and typically offers lower performance than native AWS solutions. Attaching us-west-1 VPCs directly to the ap-southeast-2 Transit Gateway is not possible across Regions.