Quick plug I'll drop in here (I manage Cloudflare's Developer Advocacy team) - in addition to Durable Objects reaching GA, we also released a great open-source codebase today to help scale your Durable Objects-based projects.

It has built-in sharding and communication between connections/shards - basically how we would recommend people build with DO if they want to hit the ground running.

Check it out on GitHub! https://github.com/cloudflare/dog