FreelanceHub

FreelanceHub is a comprehensive backend application built using Node.js, Express.js & SQL, designed to simulate the core functionalities of freelance marketplaces like UpWork. This system enables clients to create contracts with contractors, who can then perform jobs for these clients. The application facilitates seamless management of profiles, contracts, and job payments, ensuring an efficient and user-friendly workflow for both clients and contractors.

Installation & Set Up

The exercise requires Node.js to be installed. I recommend using the LTS version >= 18.

1. Clone the repository:

   git clone https://github.com/MayankAgrawal94/FreelanceHub.git
   cd FreelanceHub

2. In the repo root directory, run npm install to gather all dependencies.

3. Next, npm run seed will seed the local SQLite database. Warning: This will drop the database if it exists. The database lives in a local file database.sqlite3.

4. Then run npm start which should start the server .

Key Features:

• Profile Management: Supports both client and contractor profiles, each with a balance property.

• Contract Handling: Allows creation and management of contracts with various statuses (new, in_progress, terminated).

• Job Management: Enables contractors to get paid for jobs performed under specific contracts.

• Payment Processing: Ensures clients can pay contractors based on their balance and job requirements.

• Administrative Insights: Provides endpoints to fetch top-earning professions and highest-paying clients within a specified timeframe.

This project demonstrates a robust REST API with essential functionalities for managing job contracts and payments, serving as a foundational backend for a job contracting platform.

Data Models

All models are defined under src/models/_.js

Profile

A profile can be either a client or a contractor. clients create contracts with contractors. contractor does jobs for clients and get paid. Each profile has a balance property.

Contract

A contract between and client and a contractor. Contracts have 3 statuses, new, in_progress, terminated. contracts are considered active only when in status in_progress Contracts group jobs within them.

Job

contractor get paid for jobs by clients under a certain contract.

Technical Notes

• The server is running with nodemon which will automatically restart for you when you modify and save a file.

• The database provider is SQLite, which will store data in a file local to your repository called database.sqlite3. The ORM Sequelize is on top of it. You should only have to interact with Sequelize - please spend some time reading sequelize documentation before starting the exercise.

• To authenticate users use the getProfile middleware that is located under src/middleware/getProfile.js. users are authenticated by passing profile_id in the request header. after a user is authenticated his profile will be available under req.profile. make sure only users that are on the contract can access their contracts.

• The server is running on port 3001.

APIs description

Below is a list of the required API's for the application.

1. GET /contracts/:id - This API return the contract only if it belongs to the profile calling.

2. GET /contracts - Returns a list of contracts belonging to a user (client or contractor), the list should only contain non terminated contracts.

3. GET /jobs/unpaid - Get all unpaid jobs for a user (either a client or contractor), for active contracts only.

4. POST /jobs/:job_id/pay - Pay for a job, a client can only pay if his balance >= the amount to pay. The amount should be moved from the client's balance to the contractor balance.

5. POST /balances/deposit/:userId - Deposits money into the the the balance of a client, a client can't deposit more than 25% his total of jobs to pay. (at the deposit moment)

6. GET /admin/best-profession?start=<date>&end=<date> - Returns the profession that earned the most money (sum of jobs paid) for any contactor that worked in the query time range.

7. GET /admin/best-clients?start=<date>&end=<date>&limit=<integer> - returns the clients the paid the most for jobs in the query time period. limit query parameter should be applied, default limit is 2.

 [
    {
        "id": 1,
        "fullName": "Reece Moyer",
        "paid" : 100.3
    },
    {
        "id": 200,
        "fullName": "Debora Martin",
        "paid" : 99
    },
    {
        "id": 22,
        "fullName": "Debora Martin",
        "paid" : 21
    }
]

Contributing

If you have any suggestions or improvements, feel free to submit a pull request or open an issue.

Contact

If you have any feedback, questions, or suggestions, feel free to reach out. connect me at jobs@mayankagrawal.co.in or can DM me on LinkedIn.