Why must a chat system store a message before confirming it?
Otherwise a crash between confirming and storing leaves the sender looking at a message that no longer exists. Persist-first means any message the user sees as sent is in stable storage, and a failure produces a clear error, not a silent loss that users discover later.
Answered in
Real-Time Chat That Never Lies: Persist Before You Broadcast, and Cache the Cold StartWhy send flows must store a message before showing it, how an approximation of atomic broadcast works, and why session bootstrap needs an edge cache.
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