Overview

This service digitizes the vehicle lease agreement process, enabling electronic interactions with the contract. It facilitates data entry, validation, storage, and retrieval of contract details, tailored for Angular front-end and Node.js backend with MongoDB.

System Architecture

• Backend: Node.js with TypeScript
• Database: MongoDB
• Frontend: Angular
• Cloud Hosting: AWS (EC2, S3, Lambda, etc.)
• API Documentation: Swagger or OpenAPI

Backend (Node.js with TypeScript)

API Endpoints

• CRUD operations for lease agreements.
• Authentication and user management endpoints.
• Integration points for email/SMS services and other external APIs.

Middleware

• Validation for data integrity.
• Authentication and authorization checks.
• Error handling.

Database Integration

• Mongoose ODM for MongoDB integration.
• Schema definitions for contracts, users, vehicles, and payments.

Security

• Implement OAuth 2.0 or JWT for secure API access.
• Hashing and salting of passwords.
• HTTPS for data encryption in transit.

Logging and Monitoring

• Integration with logging frameworks like Winston or Morgan.
• AWS CloudWatch for monitoring and alerts.

Frontend (Angular)

User Interface

• Forms for entering and editing lease agreements.
• Dashboard for contract management and analytics.
• Responsive design for cross-platform compatibility.

Data Binding and Management

• Reactive forms for dynamic user input.
• State management using services or NgRx.

Client-Side Validation

• Form validation to ensure data integrity before submission.

Integration with Backend

• HTTP client to interact with Node.js APIs.
• Handling of authentication tokens and secured routes.

Database (MongoDB)

Schema Design

• User, Contract, Vehicle, Payment collections.
• Indexing for performance optimization.

Data Integrity

• Use of Mongoose for schema validation.
• Transactions for operations involving multiple documents.

AWS Cloud Infrastructure

Compute

• EC2 instances or Elastic Beanstalk for backend deployment.
• Load balancing and auto-scaling for high availability.

Storage

• S3 for storing PDFs and other static assets.
• MongoDB Atlas for managed database service.

Serverless Functions

• Lambda for running background tasks (e.g., reminders, notifications).

Networking

• VPC setup for security.
• Route 53 for DNS management.

CI/CD Pipeline

• AWS CodeBuild and CodePipeline for automated testing and deployment.

Security Considerations

• AWS IAM roles and policies for fine-grained access control.
• Regular security audits and compliance with industry standards.
• Encryption of sensitive data using AWS KMS.

Testing and Quality Assurance

• Jest or Mocha for unit and integration testing.
• End-to-end testing with Protractor or a similar tool.
• Continuous integration via AWS CodePipeline or GitHub Actions.

Documentation and Support

• Comprehensive API documentation using Swagger or OpenAPI.
• User guides for the frontend application.
• Developer guide for local setup and contribution.

Future Enhancements

• Integration with additional AWS services like RDS, Elasticsearch, etc.
• Progressive Web App (PWA) features for the Angular frontend.
• Advanced analytics and reporting features using AWS analytics tools.