Which solution will improve response times for the international customers MOST cost-effectively?
Create an AWS Direct Connect connection that has a public virtual interface (VIF) to provide connectivity from each customer’s data center to us-east-1. Route customer API requests by using a Direct Connect gateway to the ERP system API.
Set up an Amazon CloudFront distribution in front of the API. Configure the CachingOptimized managed cache policy to provide improved cache efficiency.
Set up AWS Global Accelerator. Configure listeners for the necessary ports. Configure endpoint groups for the appropriate Regions to distribute traffic. Create an endpoint in the group for the API.
Use AWS Site-to-Site VPN to establish dedicated VPN tunnels between Regions and customer networks. Route traffic to the API over the VPN connections.
Explanations:
AWS Direct Connect is a dedicated connection option, which can be costly and is generally used for high-throughput, consistent connections. It is not optimal for international customers accessing a public API, especially given cost and setup complexity.
Amazon CloudFront improves response times by caching content at edge locations close to users worldwide. This solution is cost-effective and reduces latency for international customers accessing the API.
AWS Global Accelerator improves global performance by routing traffic to the nearest Region endpoint. However, it is more costly than CloudFront and does not provide caching, making it less cost-effective for this specific use case.
AWS Site-to-Site VPN is designed for secure connections between on-premises networks and AWS, not for optimizing public API access. It also incurs additional costs and complexity and does not reduce latency for international users.
I plot that the answer is:
Set up an Amazon CloudFront distribution in front of the API. Configure the CachingOptimized managed cache policy to provide improved cache efficiency.