API Service
QuickBooks Integration (C# Service + API)
Middleware service fetching invoices from QuickBooks Desktop and syncing with fiscal API.
Client/Context
Accounting domain; 1 developer with client IT constraints (on-prem QuickBooks).
Problem
Manual export/import of invoices wasted hours and caused mismatched data.
Goals
Automate invoice sync in near real-time, reduce reconciliation errors.
Role
Designed integration service, built API bridge, tested with client data.
Tech Stack
C#, QuickBooks SDK, REST APIs, Windows Service.
Architecture
Scheduled service polls QuickBooks, transforms data, posts to API.
Implementation Highlights
- Used QuickBooks SDK for secure invoice retrieval.
- Built mapping logic to fiscal API JSON format.
- Retry/queue system for failed transmissions.
Challenges
Handling API downtime → solved with message queue & retry logic.
Results
Cut invoice sync time from 1–2 days to <5 minutes.
Timeline
1.5 months build + 2 weeks client testing.
Next steps
Extend to handle payments & multi-company sync.