Develop Payment Hub Web App

I need a secure, scalable web application that functions as a full-featured payment hub. The core of the build revolves around three must-have capabilities: • Transaction processing – real-time authorisation, capture, refund and reconciliation • User accounts management – registration, login, role-based permissions and an admin dashboard • Integration with third-party payment gateways – at minimum Stripe and PayPal, with the architecture kept modular so others can be added later without code-base disruption A modern stack is preferred (React or Vue on the front end, Node.js, Python or similar on the back end, PostgreSQL or MySQL for persistence) but I am flexible if you can justify another approach. Clean REST or GraphQL APIs, token-based authentication, and PCI-compliant handling of sensitive data are non-negotiable. Deliverables will include: 1. Source code in a private Git repository with clear commit history 2. Full database schema and migration scripts 3. Automated test suite covering critical paths 4. Docker or comparable container setup for seamless deployment 5. Concise but complete technical documentation and hand-off walkthrough I value maintainability and transparent communication, so please outline your proposed architecture, key milestones and any questions you need answered before we begin.