Backend Reliability Engineer Needed (Cloudflare Workers / D1)

We are preparing a major upgrade for an existing production mobile application built with React Native for both iOS and Android. The application currently has hundreds of active users, and the new version goals: * Offline support * Sync reliability * Optimistic UI updates * Queue-based synchronization * Duplicate prevention * Data integrity * Multi-device behavior * Backend reliability The backend is built on Cloudflare Workers and Cloudflare D1 (SQLite). Before releasing these changes, we need an experienced engineer to thoroughly review the architecture, implementation, migration strategy, and deployment approach. Responsibilities: * Review the new backend and sync architecture. * Evaluate migration risks from the current production system to the new version. * Identify potential issues affecting existing users during upgrades. * Verify backward compatibility with older app versions currently in production. * Review database schema changes, migrations, deployment strategy, and rollback plans. * Analyze risks related to data loss, duplicate records, sync conflicts, authentication, offline behavior, account migration, and slow or unreliable internet connections. * Review both frontend and backend interactions to ensure the React Native application behaves correctly across iOS and Android during upgrades. * Recommend improvements to make the rollout safer and more reliable. * Help create a deployment strategy that minimizes risk to existing users. The ideal candidate should think from a reliability, migration, architecture, and deployment perspective rather than a feature-development perspective. Preferred experience: * React Native (iOS & Android) * Cloudflare Workers * Cloudflare D1 / SQLite * Offline-first applications * Sync engines * Database migrations * Production deployments * Reliability engineering * Release management * Backward compatibility strategies * Mobile app upgrade and migration planning