Financial Disbursal Platform (NDA)
A bank-grade financial disbursal platform for state police, integrated with SBI's banking infrastructure. Backend developer on a 12-member team, serving 4 lakh+ users.
LIMS NDA & Confidential Project
Visual assets and banking integration parameters are protected per non-disclosure agreements.
The Challenge
State Police & Institutional Financial Disbursal Gateway
High-security government operations (such as West Bengal Police vendor and beneficiary payouts) require an enterprise payment gateway middleware to connect requesting systems with State Bank of India (SBI CMP) banking infrastructure. The platform needed to execute instant UPI and direct bank transfers, enforce district-level spending caps, mandate RSA-2048 / AES-128-GCM hybrid encryption, enforce Redis rate limiting, and generate automated Excel/PDF audit reports.
Key Features Delivered
Core platform capabilities connecting third-party requesting systems, SBI banking APIs, and administrative control.
LIMS Gateway
Hybrid RSA-2048 OAEP payload encryption, AES-128-GCM key hashing & RSA-SHA256 digital signatures for SBI CMP integration.
Bank-Grade Cryptography Pipeline
LIMS Gateway
High-throughput payment gateway processing direct bank account payouts and UPI disbursals with real-time status verification.
SBI CMP Direct Banking Integration
LIMS Gateway
Admin control interface to dynamically configure, monitor, and enforce monthly payment spending caps across state districts.
District Quota & Spending Control
LIMS Gateway
JWT tokens for admins + API credentials (userId, password, apiKey) for external callers with Redis rate limiting & IP whitelisting.
Dual-Layer Security & IP Whitelist
LIMS Gateway
Admin login with 6-digit OTP verification (30s cooldown, 10m timeout) and non-repudiable UpdateLog audit tracking.
Admin MFA & Audit Log Engine
LIMS Gateway
Multi-filter transaction search and 1-click export of payment summaries into formatted Excel (.xlsx) and PDF reports.
Automated Report Generation
API Endpoints
Express.js v4.21 REST endpoints across 6 module domains (payment, admin, apiUsers, district, report, misc).
Mongoose Models
MongoDB schemas managing transactional state histories, API client quotas, district caps, and admin audit logs.
Lines of Code
~4,633 LOC Node.js backend + ~7,064 LOC React 19 admin portal written in strict TypeScript.
Hybrid Encryption
Dual-layer RSA-2048 OAEP and AES-128-GCM payload protection with dynamic stage/prod PEM key switching.
My Role & Contribution
Banking Middleware & Auth Engineering
Collaborated within a 12-member engineering team — co-designing the SBI CMP payment gateway middleware, district-level payment quota controls, and dual-layer security pipelines.
Node.js, MongoDB & React 19 Stack
Built Express.js backend services (~4.6K LOC) with Mongoose models, Redis rate limiting, and a React 19 / Vite admin management dashboard (~7.1K LOC) with Chart.js analytics and Excel/PDF reports.
Hybrid cryptographic pipeline with RSA-SHA256 request signatures.
Strict rate limiting (100 req/15min) & caller IP whitelisting.
5 MongoDB schemas tracking transaction timelines & admin UpdateLogs.
Chart.js financial charts, SheetJS Excel export & PDF-Lib report generation.
Beneficiary Users
State police & government payment beneficiaries.
API Endpoints
SBI CMP bank-integrated payment APIs.
TypeScript LOC
Clean codebase across Node.js & React 19 stack.