Accelerating uncacheable dynamic traffic globally

WHAT THIS TESTS The question checks that you understand the difference between caching and network acceleration, and that you can speed up traffic that can never be cached by improving the path and terminating connections closer to the user.

A GOOD ANSWER COVERS The latency comes from the long, jittery public-internet path from Australia to us-east-1, plus the multiple round trips for TCP and TLS handshakes. Even uncacheable POST traffic benefits from terminating the client connection at an edge point of presence near the user, so the handshakes happen locally and the data then travels over the cloud provider's private, congestion-managed backbone rather than the open internet. AWS Global Accelerator and the dynamic site acceleration features of CDNs do exactly this, providing anycast entry IPs and optimized backbone routing. You can also move computation to the edge with edge functions to handle parts of the request closer to the user. Connection reuse and keep-alive between edge and origin further cut handshake overhead. The most complete fix is to stop sending the traffic across the planet at all: deploy the application in a region near Australia, such as ap-southeast-2, with data replication, turning a global round trip into a local one. Acceleration buys time and helps single-region apps, but multi-region presence is the durable answer for global latency.

COMMON WRONG ANSWERS Proposing to cache the POST responses in a standard CDN, which is impossible for dynamic, user-specific writes. Assuming a CDN only ever caches and cannot accelerate. Ignoring handshake round trips as a latency source.

LIKELY FOLLOW-UPS How does anycast routing reduce latency? What changes when you go multi-region for writes? How does TLS session resumption help?

ONE CONCRETE EXAMPLE Global Accelerator gives the app two anycast IPs; the Australian user hits a nearby Sydney edge, completing TLS locally, and the request rides the AWS backbone to us-east-1, noticeably cutting tail latency without any caching.