A Google Docs-style editor that merges concurrent edits with nothing lost and no 'resolve conflict' prompt, built on a from-scratch CRDT (Fugue algorithm) proven with property-based tests across 10,000+ randomized concurrent-edit runs. Offline-first on an IndexedDB op-log synced over WebSockets. Stack: TypeScript, React, ProseMirror, WebSockets, IndexedDB, Node.js.