CloudFront can reduce response times by caching API responses, but if the API is dynamic and not cacheable, it may not be as effective. Global Accelerator is better for improving latency when caching is not an option.

CloudFront for Dynamic content (such as API acceleration and dynamic site delivery)

While dynamic content typically has low caching potential, CloudFront reduces latency by routing requests to the nearest edge location. There is also TCP Connection Reuse, which is also beneficial for low latency.

I think that the following quote "to exchange information with the ERP system" suggest that the clients use the api not only to get, but to add and/or update ERP data. If this is the case, using a Cloudfront distribution for caching should be useless as the add/update operations must be performed by the ERP system itself. Option "C" approach is different: it's "forcing" users to access API ERP via AWS routing optimised networks by configuring the current API as an endpoint for the globally distributed endpoints groups (no need to duplicate current infrastructure or setup replication)

C. 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.

A - Direct Connect requires dedicated connections for each customer, making it expensive and impractical for a public API. B - CloudFront improves performance but caching efficiency depends on the API use case. Dynamic & personalized API responses may not benefit significantly from caching. CloudFront is best suited for static content or APIs with predictable responses. C - Global Accelerator provides a global static IP address and uses the AWS global network to route traffic optimally, reducing latency for geographically distant users. Unlike CloudFront, it works well in this case because it doesn't rely on caching contents. D - VPNs are not ideal for public APIs because they require specific setup for each customer, so high operational overhead.

C. AWS global accelerator is more suitable for cost-effective solutions to improve API respons time for int'l users by using AWS global network to optimize traffic routing. Whereas, D. AWS Cloudfront is less effective for dynamic, real-time API interactions like this ERP system.

The correct answer is C. Explanation: Option C: Correct. AWS Global Accelerator provides access via the AWS global network, reducing latency and improving performance for globally distributed users. By using Global Accelerator, you can direct global traffic to optimal AWS endpoints, offering lower latency and better connectivity compared to standard internet routing. It achieves this without modifying the API infrastructure, making it a highly cost-effective solution for improving API response times for international users.

Given that the ERP system is hosted in us-east-1 and the API is likely HTTP/HTTPS-based, Option B (Amazon CloudFront) is the best solution. CloudFront’s global edge network and caching capabilities will significantly improve response times for international customers while reducing the load on the backend EC2 instances.

https://aws.amazon.com/cloudfront/dynamic-content/

MOST cost-effectively - (ERP) system in the us-east-1 Region (one region only) will be B AWS Global Accelerator use case for one or multiple AWS regions!

How is AWS Global Accelerator different from Amazon CloudFront? AWS Global Accelerator and Amazon CloudFront are separate services that use the AWS global network and its edge locations around the world. CloudFront improves performance for both cacheable content (such as images and videos) and dynamic content (such as API acceleration and dynamic site delivery). Global Accelerator improves performance for a wide range of applications over TCP or UDP by proxying packets at the edge to applications running in one or more AWS Regions. Global Accelerator is a good fit for non-HTTP use cases, such as gaming (UDP), IoT (MQTT), or Voice over IP, as well as for HTTP use cases that specifically require static IP addresses or deterministic, fast regional failover. Both services integrate with AWS Shield for DDoS protection

MOST cost-effectively.. this is another reason to use CloudFont...

Cloudfront used for API acceleration and Dynamic content delivery

CloudFront is bettet for https

Why other options are less ideal: A. AWS Direct Connect Very expensive and complex to set up for each international customer. Designed for private, dedicated connections, typically for a single customer, not multiple public API users. Not scalable or cost-effective in this scenario. B. Amazon CloudFront CloudFront is ideal for static content (e.g., images, scripts, web pages), not dynamic APIs. CachingOptimized policy works best for cacheable responses, not for dynamic ERP APIs, which likely serve real-time data. D. AWS Site-to-Site VPN Requires customer coordination to set up VPN tunnels. Adds network complexity and operational overhead. Not cost-effective or scalable for public API access by many international users.