Django SaaS Billing & Inventory

PHP, Python, Django, Software Architecture, PostgreSQL, Payment Gateway Integration, Flutter, API Development, Payment Processing, SaaS · I’m putting together a cross-platform billing and inventory SaaS that must run smoothly on the web (React) and mobile (Flutter). The core stack is already chosen: a Django backend with a PostgreSQL database, all deployed on AWS.

Key functional blocks you’ll build and wire up:

• Subscription engine – monthly recurring plans driven by Razorpay Subscriptions API, with optional Stripe fallback, automatic invoicing, proration, and dunning logic. • GST-compliant invoice management – create, edit, email, and share invoices; integrate with the GSTN e-invoicing APIs for real-time IRN and QR code generation. • Inventory & batch tracking – receive stock, monitor quantities, lot/expiry dates, and link sales orders to inventory reductions. • Offline-first data layer – the mobile app must work without connectivity and sync seamlessly when a connection returns, resolving conflicts gracefully. • Role-based security – Admin, staff, and accountant levels with encrypted data at rest and in transit. • Reports & analytics – sales, taxes, inventory valuation, MRR, and churn visualisations downloadable as PDF/CSV. • Bilingual UI – instant Tamil/English toggle across web and mobile.

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