Invoice Management System

📝 Project Requirement

Since Covid-19, there has been a surge in online businesses. Business owners need an easy way to send invoice to their customers. Your starup needs to provide a service that sends invoices to customers. You will be using the microservice architecture to architect the system, ensuring that services are available at scale.

User Service

• Integrate third-party authentication for user sign-up and login (e.g., Auth0, Firebase Auth).
• Maintain user profiles with necessary details (e.g., name, email, wallet balance).

Invoice service

• Accept and store invoice-related details from users.
• Generate a downloadable PDF version of the invoice based on a predefined template.

Email Service

• Accept invoice details and recipient email.
• Provide an abstraction layer over multiple email service providers. If one fails, it should transparently switch to another.
• Recommended Email Providers: SendGrid, Mailgun, SparkPost, Amazon SES.

Technical Requirement:

• Use third-party authentication for user handling.
• Each service should be independent. They should be capable of operating separately and be consumed independently.
• Expose well-documented API endpoints for all services.

Frontend

• Develop a responsive web-based interface.
• Allow users to:
  • Register and log in.
  • Add funds to their wallets.
  • Create, view, and send invoices.
  • Track their wallet's transaction history.
  • View the status of sent emails (e.g., sent, delivered, failed).

🚀 Technologies

You can use any of the languange or technology listed below unless otherwise stated:

Backend

• Java Springboot
• Node.js & Express (javascript & Typescript)
• Python (Any Python stack)

Database

• MongoDB
• MySQL
• PostGre SQL

Others

• Docker

Frontend

• React
• Angular

Additional Suggestions:

• Include logging to track failures or errors in the system.
• Set up CI/CD pipelines using Github actions
• Use containerization (e.g., Docker, Docker Compose) for services to ensure a consistent development and deployment environment.

✅ Accessment Criteria

1. API Design: Clear, consistent, and documented API endpoints.
2. Code Quality: Clean, maintainable, and efficient code.
3. System Design: Scalable and resilient system architecture.
4. Error Handling: Robust handling of possible failures and errors.
5. Unit tests both on the backend and frontend

Instruction

Fork this repository All your changes should be made in a private fork of this repository. When you're done please, please:

Share your fork with the exquisapp user (Settings -> Collaborators -> Add People)

Reply to the email that asked you to do this API exercise, with a link to the repository that the exquis-test user now should have access to.