Advanced Offline Syncing Web Application

I want to build an advanced web application that works without internet and automatically syncs data when the internet comes back.

The application should allow multiple users to edit the same documents on different devices, even when some users are offline. When they reconnect, all changes should merge automatically without losing data.

Main features:

Work offline without an internet connection.

Automatically save data on the user's device.

Synchronize changes between multiple devices.

Handle multiple users editing the same document simultaneously.

Prevent data loss during network failures.

Keep document history and allow users to restore previous versions.

Support secure data storage and user permissions.

Technical requirements:

TypeScript and React

Yjs or Automerge for CRDT synchronization

IndexedDB for local storage

WebSockets or WebRTC for communication

Automated testing for synchronization and data recovery

I need a working prototype, complete source code, technical documentation, and tests.

Please explain your proposed solution, estimated cost, development timeline, and relevant experience with offline-first applications and distributed systems.

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來源：Freelancer.com | 出價次數：82 | 剩餘時間：6 日 | 專案類型：按小時