Chanchi Mercado POS

The problem

Sales, store credit and stock lived on paper; hand-kept balances invited errors, and the shop needed web orders without costly servers.

How I solved it

A React 19 SPA + PWA on Workers, Hono and D1: public catalog with search and categories, pickup orders, a store-credit ledger where balances are computed from atomic movements, and a PIN-protected admin panel.

Technology & interaction

Instant product search, category chips, credit payments validated against the debt in the same SQL transaction, and installable as a PWA.