Real-Time Collaboration With Replicache and Fly-Replay

The text discusses a solution for implementing real-time collaboration in a distributed system using Replicache, Fly Machines, and Fly.io's feature called "fly-replay". It provides an example of a collaborative real-time todo app that uses these technologies to enable efficient communication between clients and backend servers running on different VMs. The architecture includes a router that leverages fly-replay to direct WebSocket connections to the appropriate backend machine for each document, allowing users to connect seamlessly without needing to know the specific location of their data.