Built and launched a multi-tenant QR ordering and POS platform for restaurants and retail. Customers scan a QR code, browse, and order without an app or account, while staff manage real-time kitchen and fulfillment queues. I developed the Nuxt 4 frontend and backend, Prisma/PostgreSQL data model, Redis workflows, guest sessions, OAuth/MFA/RBAC security, Tap Payments integration, verified webhooks, role-based dashboards, testing, logging, and production monitoring.