I built t4, a datastore that stores its WAL and snapshots in S3.

Instead of traditional storage, it writes append-only segments to object storage and reconstructs state from checkpoints + WAL.

A side effect of this model is that the database becomes naturally versioned: you can restore any past state, branch from any point (with copy-on-write) and replay history

I started this as an experiment to replace etcd in Kubernetes, but it’s evolving into a general-purpose versioned state store.

Curious what people think about it and appreciate any feedback!