Darren Walters App
The Darren Walters App is a brand-new, revolutionary way, to buy, sell, refinance, and invest in property in Australia.
About the Project :
The Darren Walters App is a comprehensive financial platform designed to assist users in achieving property-related goals such as buying a home, purchasing investment properties, or refinancing. It features seamless account creation, dynamic questionnaires, document uploads with OCR analysis, borrowing capacity calculations, and integrations with external services for data verification and risk assessment. The app supports multi-applicant processes, admin backend management, and is available on web, Android, and iOS platforms.
My Role :
Backend Developer (Node.js/NestJS)
Tech Stack :
Key Features :
Account creation with mobile number verification via Twilio SMS OTP and biometric options
User intent selection for financial goals (buy home, investment property, refinance) with customizable backend options
Dynamic questionnaires collecting personal, financial, property, and equity details, integrated with mapping APIs
Multi-applicant support with primary/secondary roles, handover capabilities, and progress tracking
Document upload system with OCR (using AWS Textract and custom DW Engine) for payslips, bank statements, and IDs
Integration with Illion API for bank statement verification and credit checks
Borrowing capacity calculator based on collected data, income, liabilities, and superannuation details
Admin backend for user management, application editing, lender onboarding, and analytics
In-app messaging system for user-admin communication with file attachments and notifications
IDVAULT for document verification, including country detection, structure analysis, and error identification
Challenges Faced :
One of the main challenges was replicating Microsoft Excel’s financial functions (PV, FV, PMT, etc.) in JavaScript and ensuring the outputs matched Excel exactly, along with replicating Excel’s micro-level logic
Implementing secure and compliant data processing for financial documents while adhering to regulations
Handling dynamic questionnaires and modular financial products that adapt to user selections
Coordinating multi-applicant workflows with role handovers and logging transaction history
Integrating OCR and machine learning for accurate extraction and analysis of varied document formats
Managing file uploads with compression, size limits, and exclusions for security
Ensuring seamless real-time notifications and messaging across platforms using Socket.io and Firebase
Key Learnings :
Developing scalable backend architectures with NestJS and Node.js for financial applications
Integrating third-party APIs like Twilio for OTP, Illion for bank data, and AWS Textract for OCR
Implementing secure authentication mechanisms using JWT, OTP, and biometric re-authentication
Building machine learning components for financial data categorization, pattern recognition, and continuous learning
Built an open-source Node.js npm package called finmaster that includes the major financial functions of Microsoft Excel.
Optimizing database management with MongoDB for handling user profiles, applications, and document archives
Creating modular systems for customizable forms, goals, and lender prerequisites in the admin panel