Building Offline-First Desktop Apps

When I built MoraBizSuite for businesses in areas with unreliable internet, I learned that offline-first isn't just a feature—it's an architecture.

The Core Principles

1. Local-First Data

All data lives locally by default. SQLite is your friend.

// Write to local first, always
await localDb.insert(transaction);
// Sync in background when online
syncQueue.enqueue(transaction);

2. Conflict Resolution

Conflicts are inevitable. CRDTs (Conflict-free Replicated Data Types) provide mathematical guarantees.

3. Optimistic UI

Never block on network. Show the result immediately, reconcile later.

Sync Strategy

1. Track all local changes with timestamps and UUIDs
2. On connectivity, send batch of changes
3. Receive server changes and merge
4. Use vector clocks for ordering

Real-World Lessons

• Test with network throttling from day one
• Build admin tools for conflict resolution
• Log everything for debugging sync issues
• Plan for the "split brain" scenario

The investment in offline-first architecture pays dividends in user trust and reliability.