Client & billing CRM

About the project

The single source of truth for the company’s clients. It syncs customers with QuickBooks, generates invoices from subscriptions, and pulls read-only data from their device management, ISP and VOIP suppliers. Built solo and hosted in Sydney so client data stays in Australia.

What I built

• Two-way QuickBooks customer sync over OAuth, with invoices generated from client subscriptions and line items
• NinjaOne device-management integration reading organization data through OAuth2 client credentials
• A shared integration client so InvoiceNinja and an ISP integration slot in the same way
• 21 SQL migrations with row-level security on every table
• A live integration health probe and a sync log for troubleshooting failed syncs