💸 Simulated Digital Banking System for Secure Transactions

Created for Charles Schwab Interview (NOT AFFILIATED WITH CHARLES SCHWAB (YET) - JUST A PROJECT TO SHOWCASE)

A full-stack banking simulation platform where users can create accounts, perform secure transactions, and sign high-value envelopes (> $10,000) for verification. Built with Spring Boot, Angular, and MySQL, the project demonstrates JWT-based authentication, role-based access control, and a modern responsive UI — containerized using Docker.

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🚀 Features

🔐 Authentication

• Secure JWT-based login / signup
• Spring Security protecting all sensitive endpoints
• Role-based authorization (USER / ADMIN)

💳 Accounts & Transactions

• Create, delete, and manage user accounts
• Send and receive transactions between users
• Flag and route high-value transactions (> $10,000) to an approval system
• Deposit and withdraw funds safely

✉️ Envelopes & Signers

• Automatically creates an envelope for flagged transactions
• Both sender and receiver must digitally sign to approve
• SHA-256 based digital signature simulation

🖥️ Frontend (Angular)

• Clean dashboard UI with:
• Account balance overview
• Sent / Received transactions
• Interactive modals for transfers and deposits
• Responsive design using Montserrat typography

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🧩 Tech Stack

Layer	Technology
Frontend	Angular 17, TypeScript, HTML, CSS
Backend	Spring Boot 3, Spring Security, JPA, Hibernate
Database	MySQL
Auth	JWT (Bearer Token)
Deployment	Docker Compose
Build Tools	Maven, Node.js

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⚙️ Installation & Setup

Prerequisites

• Java 21+
• Node.js 18+
• MySQL 8.0+
• (optional) Docker Desktop

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Usage

Build using Docker

docker compose up --build

To Stop:

docker compose down

Go To: http://localhost:4200

If you want to just test locally instead, just follow the following directions 👇

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Set Up Backend

1. Build backend

cd transaction_validator

and set your database credentials in:

src/main/resources/application.properties

Example:

spring.datasource.url=jdbc:mysql://localhost:3306/transaction_validator
spring.datasource.username=root
spring.datasource.password=password
spring.jpa.hibernate.ddl-auto=update

2. Start backend

mvn spring-boot:run

Now the app will begin to run on http://localhost:8080 or if you want to use Swagger, try http://localhost:8080/swagger-ui.html

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Set Up Frontend

1. Build and Start Frontend

cd frontend
npm install
ng serve

2. Test Now the frontend will begin to run on http://localhost:4200

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🧾 Example Use Flow

1. Sign up → automatically creates user
2. Log in → retrieves JWT token (saved in localStorage)
3. Create account → initial deposit
4. Send a transaction:
   • If ≤ $10,000 → auto-approved
   • If > $10,000 → generates envelope requiring signatures
5. Both users sign → funds transferred + envelope marked “COMPLETED”

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👨‍💻 Author Saman Sathenjeri
📧 https://www.linkedin.com/in/saman-sathenjeri/