Building Warp (https://warp.thegeeksquad.io), a storage engine where each entity is its own actor with its own SQLite shard.
I've been doing DDD and event sourcing for years but always had to squeeze aggregates and domain events into Postgres tables. I kept looking at what scaling would mean with CockroachDB or ScyllaDB and it scared me. So I asked what happens if you just make SQLite the storage and let the BEAM handle concurrency, one actor per entity.
Turns out it works pretty well. 1.5M events/sec on an M1 in Docker with 5 cores. ScyllaDB on the same hardware does 49K. Written in Gleam, but there's a TypeScript SDK if you just want to use it from Node.
How do you solve HA?
BEAM distribution + consistent hashing. Entities are assigned to nodes by their ID. If a node goes down, the hash ring updates and surviving nodes pick up its entities. Litestream continuously streams SQLite WAL changes to S3 so you can restore from the last segment.
The clustering and rebalance coordinator are implemented and tested with multi-node BEAM peers, but I'll be honest, I haven't run it in a multi-server production deployment yet. Single-node with Litestream backup is what I'm running in production right now. Recovery from backup takes seconds, not minutes.
True multi-node HA is architecturally ready but not battle-tested at scale yet. v0.1.