Content Delivery Network (CDN)
I run through at a high level what a CDN is and how it enables lower latency for your clients. Then I share with you what has worked for me when using a CDN to deliver low latency web sites. Also using a CDN can actually enable a more cost effective solution at scale.
Enable your application to scale beyond the capabilities of your platform. By using the queue sharding pattern you are able to scale a message bus up to many magnitudes higher throughput.
If you are really interested in leveraging sharding I would check for open source solutions that have already built this logic.