Full-Stack Developer: Offline-First POS, Inventory & Accounting System (Auto Parts, FBR Integration)

We're building a custom ERP/POS system for an auto parts retail business in Pakistan operating two related legal entities that share a single inventory pool but require separate accounting books. The system needs to run reliably in an environment with unreliable internet, while staying synced to the cloud and compliant with FBR's e-invoicing requirements. We're looking for an experienced full-stack developer to join as a hands-on contributor/pair alongside our existing team to help design and build core modules. What We're Building POS / Sales — point-of-sale terminal for daily retail transactions Inventory Management — shared stock pool across two business entities, part fitment logic Purchasing & Returns — vendor purchase orders, stock returns Accounting & Reports — separate books per entity, standard financial reports FBR Compliance — invoice submission integrated with FBR's POS system (per SRO 288/2026), including an offline queue that submits within the required 24-hour window once connectivity returns Key Architecture Requirements Offline-first, local-server-plus-cloud-mirror design: a local server/database at the shop keeps the business running through internet outages, with automatic sync to a cloud instance when connectivity is available Simple, non-technical UX: end users are blue-collar retail staff with no technical background — the interface must be dead simple Multi-entity accounting: two legal entities, one shared inventory pool, clean separation of financial records Data migration: importing data from the client's existing system Our Stack Electron + React (desktop/terminal app) Node.js / TypeScript (Express or Fastify) Local PostgreSQL + Supabase (cloud sync via outbox pattern) Prisma or Drizzle ORM React dashboard (deployed on Vercel) What We're Looking For Strong experience with Electron + React desktop apps Solid backend skills in Node.js/TypeScript, relational schema design (PostgreSQL) Experience building offline-first / sync-capable applications (queue-based sync, conflict handling, outbox pattern, etc.) Comfortable working from detailed functional specs and asking sharp clarifying questions Bonus: experience with POS systems, retail inventory software, or government e-invoicing/tax integrations Bonus: familiarity with the Pakistani business/tax environment (FBR, GST) — not required, but a plus Project Status Requirements discovery, documentation, and system design are already underway — you won't be starting from a blank page. We have detailed module specs and data models ready to hand off, with a short list of open questions we're actively resolving with the client. How to Apply Please share: Relevant experience with Electron/React desktop apps and offline-sync architectures A short note on how you'd approach sync/conflict resolution between a local DB and a cloud mirror Your availability and estimated hourly rate or project rate Looking forward to finding a strong collaborator for this build.