https://www.youngju.dev/blog 천천히 올바르게. AI Researcher & DevOps Engineer Youngju's tech blog. GPU/CUDA, LLM, MLOps, Kubernetes AI workloads, distributed training, and data engineering. ko fjvbn2003@gmail.com (Youngju Kim) fjvbn2003@gmail.com (Youngju Kim) Mon, 25 May 2026 00:00:00 GMT https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive.en https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive.en The 2026 web does not sync with a "Save" button anymore. The simultaneous-editing problem that Google Docs first solved with OT (Operational Transform) became routine through Figma multiplayer, Linear local-first, Notion live cursors, and tldraw realtime canvases. This essay walks the full landscape — CRDT theory (CmRDT vs CvRDT, vector clocks, Lamport timestamps), the internal structures of Yjs/Automerge/Loro text CRDTs, the operational models of Liveblocks/PartyKit/Hocuspocus, WebSocket vs WebRTC, presence/awareness protocols, and the positioning of Fluid Framework, ShareDB, and Replicache. With the Ink & Switch local-first manifesto, Martin Kleppmann's papers, and the post-Vercel Liveblocks/PartyKit landscape. Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) crdtrealtime-collaborationliveblockspartykityjsautomergelorosharedbreplicachetldrawexcalidrawoperational-transform https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive.ja https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive.ja 2026年のウェブはもはや「保存ボタン」で同期しない。Google DocsがOT(Operational Transform)で実現した同時編集は、Figmaのマルチプレイヤー、Linearのローカルファースト、Notionのライブカーソル、tldrawのリアルタイムキャンバスを通じて当たり前になった。本稿はCRDT理論(CmRDT vs CvRDT、ベクタークロック、Lamport timestamp)からYjs・Automerge・Loroのテキスト CRDT 内部構造、Liveblocks・PartyKit・Hocuspocusの運用モデル、WebSocket vs WebRTC、presence/awarenessプロトコル、Fluid Framework・ShareDB・Replicacheのポジショニングまでを一気通貫で整理する。Ink & Switchのローカルファースト運動、Martin Kleppmannの論文、VercelによるLiveblocks・PartyKit連携後のランドスケープも踏まえて。 Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) crdtrealtime-collaborationliveblockspartykityjsautomergelorosharedbreplicachetldrawexcalidrawoperational-transform https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive https://www.youngju.dev/blog/culture/2026-05-25-realtime-collab-crdt-liveblocks-partykit-yjs-automerge-loro-2026-deep-dive 2026년의 웹은 더 이상 "저장 버튼"으로 동기화하지 않는다. Google Docs가 OT(Operational Transform)로 시작했던 1인 vs 다수의 동시 편집은, Figma의 멀티플레이어, Linear의 로컬-퍼스트, Notion의 라이브 커서, tldraw의 실시간 캔버스로 일상이 되었다. 이 글은 CRDT 이론(CmRDT vs CvRDT, 벡터 클럭, Lamport timestamp)부터 Yjs·Automerge·Loro의 텍스트 CRDT 내부 구조, Liveblocks·PartyKit·Hocuspocus의 운영 모델, WebSocket vs WebRTC, presence/awareness 프로토콜, Fluid Framework·ShareDB·Replicache의 포지셔닝까지 한 번에 정리한다. Ink & Switch의 로컬-퍼스트 운동, Martin Kleppmann의 논문, Vercel의 Liveblocks·PartyKit 인수 후 풍경까지. Mon, 25 May 2026 00:00:00 GMT fjvbn2003@gmail.com (Youngju Kim) crdtrealtime-collaborationliveblockspartykityjsautomergelorosharedbreplicachetldrawexcalidrawoperational-transform