Overview

The Mobile Banking App is a secure and user-centric financial application designed to offer customers a full range of digital banking services from their smartphones. From fund transfers and balance checks to bill payments and transaction history, the app provides seamless access to essential banking functions in real time.

My role involved building the backend architecture to ensure transactional integrity, user data protection, and efficient service delivery across all supported features.

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Key Backend Features

Secure Authentication & Authorization

  Implemented multi-factor authentication (MFA) using OTPs and biometric validation. Used JWT for secure session management, combined with encrypted storage of sensitive credentials.

Account & Transaction Management

  Developed core APIs to handle account data, transaction processing, fund transfers, and account statements. Ensured atomicity and consistency using ACID-compliant transactions.

Real-Time Balance Updates

  Enabled instant balance reflection and transaction confirmations using real-time synchronization with bank systems.

Fraud Detection System

  Integrated behavior-based anomaly detection logic to flag suspicious transactions or access patterns and notify users immediately.

Payment Integration

  Supported mobile money APIs and integrated with third-party bill payment systems for services such as electricity, water, and airtime.

Audit & Logs

  Implemented a comprehensive logging system for transaction audits, user actions, and system events — critical for both security and regulatory compliance.

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Technologies Used

Backend: Node.js with Express

Database: PostgreSQL (for relational integrity), Redis (for caching)

Authentication: JWT, OTP via Twilio, bcrypt for password hashing

Payments: Mobile Money APIs (e.g., M-Pesa), Stripe

Security: HTTPS, rate limiting, data encryption, OWASP standards

Deployment: Docker, Kubernetes (for scaling), AWS EC2 and RDS

Monitoring: Prometheus + Grafana for system health and alerts

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Impact

The backend I developed enabled thousands of users to securely manage their finances anytime, anywhere. By ensuring data privacy, transaction accuracy, and high availability, the Mobile Banking App significantly improved digital engagement and reduced the need for in-person banking. This project solidified my expertise in secure, high-stakes backend systems and financial tech development.