Backend Developer Role Technical Assessment

Scenario

Fitness+ offers gym memberships with various billing structures. Some memberships are annual with a single upfront payment, while others have monthly dues. Additionally, members can subscribe to optional add-on services (personal training sessions, towel rentals) with separate monthly charges. Here's the twist:

• For new members, the first invoice combines the annual membership fee with the first month's charges for any add-on services they choose.
• In subsequent months, only the monthly charges for the add-on services are billed.

Task

Develop a backend system that implements the following functionalities based on your expertise in these frameworks to build a robust and scalable backend API. Consider Express.js and MongoDB, well-documented RESTful APIs, and you can use your Gmail SMTP server to send out the mails.

1. Data Model

Design a data model to store information about gym memberships, including:

• Membership ID (unique identifier)
• First Name
• Last Name
• Membership type (e.g., Annual Basic, Monthly Premium)
• Start date
• Due date (for annual memberships) or monthly due date (for add-on services)
• Total amount (for annual memberships) or monthly amount (for add-on services)
• Member email address
• IsFirstMonth (boolean flag indicating if it's the first month of the membership)
• (Optional) Link to the detailed membership invoice

2. Cron Job Implementation

Develop a cron job that will run periodically (e.g., daily) to check for upcoming membership fees. The cron job should:

• Query the database for memberships with upcoming due dates.
• Differentiate between annual memberships and add-on services, considering the IsFirstMonth flag.

For new members (first month):

• Calculate the reminder date (e.g., 7 days before the due date) based on the annual membership due date.
• Send an email reminder with the membership type, total amount for the combined annual fee and first month's add-on service charges, and a link to the full invoice detailing both.

For existing members (subsequent months):

• Check if the current date falls within the month for which the add-on service applies.
• If yes, send an email reminder with the service name, monthly amount, and a link to the invoice for that specific month's add-on service charge.

3. Email Functionality

Implement a mechanism to send email reminders using an email service provider (ESP) or a local mail server (your choice). The email should contain:

• Subject: Fitness+ Membership Reminder - [Membership Type]
• Body: A message reminding the member about the upcoming payment, including the membership details (type, due date for annual or month for add-on services), and a link to the relevant invoice. Clearly differentiate between the first month's combined invoice and subsequent month's add-on service invoices in the message.

Solution Overview

This project implements a backend system to handle the membership and billing scenarios described above. It includes:

1. A data model to store membership information.
2. A cron job to send email reminders for upcoming payments.
3. Email functionality to send reminders using a Gmail SMTP server.

Endpoints

Create Membership

• URL: https://fitness-plus-backend.onrender.com/api/v1/member/membership
• Method: POST
• Description: Create a new gym membership.
• Request Body:

  {
    "email": "[email protected]",
    "firstName": "Test",
    "lastName": "Tester",
    "membershipType": "Annual Basic",
    "startDate": "2024-06-14",
    "dueDate": "2024-06-27",
    "monthlyDueDate": "2024-06-20", 
    "totalAmount": 1500,
    "monthlyAmount": 500
  }
  

1. Clone the repository: git clone https://github.com/kobiowuquadri/express-mvc-starter.git

2. Install dependencies: npm install

3. Create a .env file and configure your environment variables, check .env.example for the sample

4. Start the server: npm run dev

Contributing

Feel free to contribute by submitting pull requests to enhance the functionality of this project.

License

MIT License