FinTech Dev Needed for Real-Time Payments App

Job Title: FinTech Software Developer – Real-Time Payments App MVP (NPP / PayTo API) Project Description: We are a fast-moving FinTech startup building a disruptive real-time mobile payment application for the Australian retail market. We need an experienced FinTech Lead Developer / Architect to build our backend Minimum Viable Product (MVP). The app allows users to scan merchant QR codes to trigger instant, bank-to-bank retail payments using Australia's New Payments Platform (NPP), PayTo, and PayID infrastructure. Key Responsibilities: Integrate third-party Australian Banking-as-a-Service (BaaS) REST APIs (e.g., Monoova, Zepto) and webhooks. Implement an ISO 20022-compliant payload to generate secure, dynamic merchant QR codes. Design a secure backend (Node.js, Go, or Python) with AES-256 encryption, OAuth 2.0, and device biometric token validation. Deploy and debug end-to-end payment simulations inside the SWIFT/NPP developer sandbox. Required Experience: Proven track record building digital wallets, payment gateways, or core ledger systems (UPI or NPP experience is a massive plus). Expert-level backend skills paired with robust databases (PostgreSQL/MySQL) and secure caching (Redis). Strong understanding of financial data security and protection standards. Scope & Budget: Duration: 2-3 months (Milestone-based delivery). Budget: Competitive / Based on expertise. Note: Shortlisted candidates must sign an NDA before receiving the full technical brief. Mandatory Screening Question: "Please briefly describe a previous project where you integrated a financial transaction API, and explain how you handled webhook failures or transaction drop-offs in that system."