Loan Management System (LMS)

This repository implements a complete Loan Management System (LMS) comprising a Borrower Portal and an Internal Operations Dashboard with role-based access control (RBAC).

Technology Stack

• Frontend: Next.js 16 (App Router), TypeScript, Tailwind CSS
• Backend: Node.js, Express.js, TypeScript
• Database: MongoDB (via Mongoose ODM)
• Authentication: JSON Web Tokens (JWT) & bcryptjs hashing

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Key Modules & Roles

1. Borrower Portal

• Authentication: Full registration and sign-in.
• Application & Underwriting: Personal profile collection. Upon submission, an automated Business Rule Engine (BRE) enforces the following eligibility rules:
  1. Age: Must be between 23 and 50 (inclusive).
  2. Monthly Income: Must be at least ₹25,000.
  3. PAN Number: Verified against standard regular expression ^[A-Z]{5}[0-9]{4}[A-Z]{1}$.
  4. Employment Status: Must be Salaried (rejects Unemployed and Self-Employed). If any check fails, the loan status is immediately set to BRE_Rejected with a detailed audit note.
• Income Verification Document: Upload pay slip (formats: PDF, JPG, PNG; max size: 5 MB).
• Loan Configurator: Interactive sliders to select:
  • Principal: ₹50,000 to ₹500,000
  • Tenure: 30 to 365 days
  • Interest Math: Uses a fixed 12% per annum simple interest: $$\text{Interest} = \text{Principal} \times 0.12 \times \frac{\text{Tenure (Days)}}{365}$$ $$\text{Total Repayment} = \text{Principal} + \text{Interest}$$
• Repayment Simulation: Borrowers can submit installments directly from the dashboard (updating payment history and outstanding balance) to simulate repayment.

2. Operations Dashboard Modules

Enforces role-based permissions (RBAC) on both frontend page elements and backend API endpoints:

• Sales: Tracks registered borrowers who have not yet submitted active loan applications (potential leads, including those rejected by the automated BRE).
• Sanction: Audits active applications, inspects uploaded salary slips, and clicks Approve (Sanction) or Reject with custom underwriting notes.
• Disbursement: Reviews sanctioned applications and releases funds (Disburse), changing status to active (Disbursed).
• Collection: Monitors active payments, logs recoveries, and prints payments history.
  • Auto-Closure Rule: Once total repayments meet or exceed the total repayment goal, the loan status automatically transitions to Closed.
• Admin: A consolidated control panel featuring statistics (Counts of state, total disbursed amount, total collections, outstanding portfolio) and access to all module interfaces.

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Pre-seeded Credentials

To make evaluation quick and seamless, the database is pre-populated with accounts for all roles. All accounts use the password: Password123

Role	Email Login	Password	Description
Admin	admin@lms.com	Password123	Full access to all dashboard panels & statistics
Sales	sales@lms.com	Password123	Access to the Sales Leads pipeline
Sanction	sanction@lms.com	Password123	Underwriter review and approval desk
Disbursement	disbursement@lms.com	Password123	Releases funds for sanctioned applications
Collection	collection@lms.com	Password123	Recovery tracking and logging installment payments
Borrower	borrower@lms.com	Password123	Pre-registered borrower template profile

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Installation & Running

Prerequisites

• Node.js (v20+ recommended)
• MongoDB running locally on port 27017

1. Database Seeding & Backend API

In a new terminal shell:

# Navigate to backend
cd backend

# Install dependencies
npm install

# Run database seed (Creates the pre-seeded role accounts above)
npm run seed

# Start the Express server (Hot reload enabled on http://localhost:5000)
npm run dev

2. Frontend client

In another terminal shell:

# From workspace root
npm install

# Run the Next.js development client (Runs on http://localhost:3000)
npm run dev

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Verification & API Endpoints

Automated Rule Engine Checks

Verify by applying for a loan with:

• Age: 20 (Expected Status: BRE_Rejected)
• Monthly Salary: 20000 (Expected Status: BRE_Rejected)
• PAN Card: INVALID123 (Expected Status: BRE_Rejected)
• Employment: Self-Employed (Expected Status: BRE_Rejected)

Simple Interest Calculations Check

• Principal: ₹1,00,000
• Tenure: 180 Days
• Formula: $100000 \times 0.12 \times \frac{180}{365} = 5917.8082...$
• Expected Interest: ₹5,917.81
• Expected Total Repayment: ₹1,05,917.81