i am working on very smol deployments, where a server may use two or so replicated sqlite databases instead of a db server like postgres to seamlessly move from single to multi-node arrangements as needed. there is a clear performance limit here, but the goal is not to serve a huge number of clients. just to do as much as possible with a small number of useful components that can be upgraded to handle up to medium size workloads, without difficult data conversions or migrations. scaling beyond that point should be done via federation.