Offline-First2026

InspectSync

Built the two-phase push-pull sync protocol with field-level LWW conflict resolution and the private-by-default S3 media presigning system. Also architected the SQLite-backed idempotency layer for safe retry handling.

Role
Architect — sync protocol, backend, mobile client
Timeline
2026 · Ongoing
Stack
FlutterNode.jsPrismaRedisPostgreSQLDriftBullMQAWS S3
01

Screens & Architecture

Sync status HUD
Screen 01 · Sync status HUD
Offline inspection form
Screen 02 · Offline inspection form
02

The Problem

Inspection teams work in remote sites with flaky or zero connectivity. Existing tools lost edits, duplicated records, or overwrote each other on reconnect.

03

How I built it

  • Architected a two-phase push-pull sync protocol with field-level LWW conflict resolution.
  • Implemented private-by-default media via AWS S3 request presigning with 24h expiry.
  • Built a Redis-backed idempotency layer to make retries safe under duplicated writes.
  • Designed the Obsidian Command UI system tuned for high-glare field use.
04

Outcome

  • Zero data loss across pilot deployments in low-connectivity environments.
  • Reduced backend load ~30% by moving large media uploads off the API path via presigning.