> I swear I've looked into firebase multiple times and I have no idea how they actually detect and handle conflicts. They just hand-wave that it works offline..

> I swear I've looked into firebase multiple times and I have no idea how they actually detect and handle conflicts. They just hand-wave that it works offline... not that comforting. My understanding is (and please correct me if I'm wrong), firebase just does ACID by versioning everything. A write says "Update this value (at server version X) to value Y". The server can detect if version X is outdated, and use that to reject the conflicting write. So if you go offline and change something, and someone else changes the same value, when you come online and share your change it'll be rejected by the server. The client can optionally be intelligent in this case, and merge the conflicting values locally then re-submit if it wants to. Thats enough to implement OT on top of firebase, but the architecture means clients can't sync directly with each other. And its a bit janky if users are offline for too long, or if the client isn't written to handle retry / conflicts in a sensible way.