@justindrake asked me why we don't use DA layers instead of Snapchain. I've heard the question a few times, so here's the answer. 

Snapchain is a storage layer for Farcaster data. Every like, cast, reaction you post is stored there and propagated to all apps in real time.

Technowatermelon. Elder Millenial. Building Farcaster. 

nf.td/varun

DA layers aren't really designed to handle this. 

They're more like flat file stores that you push immutable blobs to. This works really well for an L2 trying to make its data available for future validation. But its not good for a network trying to stream real-time updates that are mutating state frequently.

If you tried to use a DA to be the primary store of Farcaster data, you'd get very large disk size, slow replication and high costs. 

The one area where DA might be useful is to store archival data when they get pruned from nodes, which we may explore in the future. But honestly, S3 might be "good enough" for this use case

Social data tends to mutate often. People like things and then unlike them all the time. They also exceed rate or storage limits and their older content needs to be cleared out. 

Snapchain's main innovation is handling this in a very performant way so that the bytes on disk and over the network are minimized. This is what makes Farcaster scalable

This is a really good take - what's the target performance for Snapchain?  Say in rounds/second or MB/s?

DA layers may not provide the same real-time propagation of data across apps like Snapchain does