GST-Compliant Secure POS System

I’m commissioning a ground-up build of a point-of-sale platform designed for an Australian retail shop that needs to stay fully GST compliant while remaining affordable to run. From day one the software must log staff in securely, encrypt all sensitive data, and back itself up automatically. Payments at launch have to include cash, card, digital wallets and the main buy-now-pay-later providers available in Australia. Staff will operate everything from a tablet, so the interface must be touch-first and highly responsive. To keep delivery clear I’m splitting the work into three consecutive phases: • Phase 1 delivers the core retail workflow—product catalogue, inventory tracking, sales screens and ATO-ready invoicing. • Phase 2 layers in purchasing modules, supplier records, customer credit handling and a clean reporting suite. • Phase 3 adds advanced analytics, true offline capability with automatic synchronisation once the connection returns, plus multi-store support. I’ll supply UI sketches, GST rules and any required API keys for payment gateways. You’ll handle architecture, coding, basic UI styling, automated test coverage and packaging for effortless deployment. All data must be protected in transit and at rest, and regular encrypted off-site backups need to run without user input. Low ongoing cost is critical, so keep third-party fees to a minimum and flag any licensing up front. Please outline the tech stack you prefer, how you’ll tackle offline sync and what milestones you suggest for each phase. I’m ready to get started as soon as we agree on the plan. Budget: AUD 250–750