Textile & Trading Co. (anonymised) was running their entire operation - sales, purchases, GST invoices, and payment tracking — across handwritten ledgers and Excel sheets, with no audit trail or real visibility into outstanding balances. The goal was to replace this with a structured, secure digital system built around real business workflows.
The system was designed as a split architecture: public and admin surfaces are deployed as completely separate services. Admin APIs are not just protected - they are physically absent from the public service. The admin backend runs behind a Tailscale VPN, making it unreachable at the network level without device-level access.
Core business rules are enforced at the backend and database level. Payment status is never accepted from the frontend - it is derived from transactions, with PostgreSQL generated columns ensuring financial data cannot drift out of sync.
The project was delivered end-to-end as a solo effort - from requirement gathering and system design to deployment - balancing real-world constraints like cost (₹0 security layer), usability, and operational reliability.