Backend Internship Project

📖 Description

Backend application created on NestJS for internships.

⚙️ Installation

# 1. Clone the repository:
git clone https://github.com/YOUR_USERNAME/backend-internship.git

# 2. Install dependencies:
npm install

# 3. Create a `.env` file based on `.env.sample`
cp .env.sample .env.development # Linux / MacOS / WSL
copy .env.sample .env.development # Windows (PowerShell)

# 4. Fill in the environment variables in `.env.development`:
code .env.development # Open the file in your editor, e.g.:

🚀 Launching the application

Development mode

# 1. Start PostgreSQL and Redis via Docker
npm run docker:dev

# 2. Start the NestJS application
npm run start:dev

Production mode

npm run build
npm run start:prod

The application will be available at: http://localhost:5000

📘 API Documentation (Swagger)

This project uses Swagger for automatic API documentation. Swagger UI provides an interactive interface for exploring and testing API endpoints.

# Swagger docs are auto-generated from controllers and DTOs via decorators.
http://localhost:5000/api/docs

🐳 Docker

Docker is used only for local infrastructure (PostgreSQL + Redis). The NestJS application runs directly via Node.js.

Start local infrastructure (development)

# Start PostgreSQL + Redis in background
npm run docker:dev

# Stop containers
npm run docker:down

# Stop containers and delete volumes (clears database data)
docker compose down -v

Note for VS Code Docker extension users: The "Run All Services" button requires a .env file in the project root. Create it by copying your development environment:

cp .env.development .env

Services included

Service	Port	Description
PostgreSQL	5432	Main database
Redis	6379	Cache and quiz answers
RedisInsight	5540	Redis UI at http://localhost:5540

🗄️ Migrations

Teams for working with migrations

# Migration generation
npm run migration:generate src/database/migrations/YourMigrationName

# Applying migrations (development)
npm run migration:run:dev

# Applying migrations (production)
npm run migration:run:prod

# Rollback of the last migration (development)
npm run migration:revert:dev

# Rollback of the last migration (production)
npm run migration:revert:prod

# View all migrations and their status (development)
npm run migration:show:dev

# View all migrations and their status (production)
npm run migration:show:prod

🌱 Database Seeding

For local development, you can populate the database with fake data using the built-in seeder.

⚠️ Warning: Running the seed will truncate all tables and replace existing data.

# Seed the database (development)
npm run seed:dev

The seeder creates fake data in the following order:

1. Users — test accounts with auth records
2. Companies — companies with members and roles
3. Invitations & Join Requests — pending requests between users and companies
4. Quizzes — quizzes assigned to companies
5. Attempts — quiz attempts with scores and analytics data

☁️ AWS Deployment

Infrastructure

Service	Provider	Purpose
EC2 (t3.micro)	AWS	Application server
RDS PostgreSQL (db.t4g.micro)	AWS	Production database
S3	AWS	File storage
Redis	Upstash	Cache & quiz answers
Domain + SSL	Namecheap + Let's Encrypt	HTTPS

Prerequisites

• AWS account with EC2, RDS, S3 configured
• Upstash Redis database created
• Domain with A records pointing to EC2 public IP
• SSH key pair (.pem file) for EC2 access

Manual deployment steps

# 1. Connect to EC2 via SSH
ssh -i your-key.pem ec2-user@YOUR_EC2_PUBLIC_IP

# 2. Install dependencies (first time only)
sudo yum install -y git nodejs nginx
sudo npm install -g pm2

# 3. Clone the repository
git clone https://YOUR_TOKEN@github.com/YOUR_USERNAME/YOUR_REPO.git
cd YOUR_REPO

# 4. Install project dependencies
npm install

# 5. Create production environment file
nano .env.production
# Fill in all variables from .env.sample with production values

# 6. Build the application
npm run build

# 7. Run database migrations
NODE_ENV=production npm run migration:run:prod

# 8. Start the application with PM2
NODE_ENV=production pm2 start dist/main.js --name backend

# 9. Save PM2 process list (auto-restart on reboot)
pm2 startup
pm2 save

Nginx configuration

server {
    listen 80;
    server_name your-domain.com api.your-domain.com;

    location / {
        proxy_pass http://localhost:5000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }
}

SSL certificate (Let's Encrypt)

# Install Certbot
sudo yum install -y certbot python3-certbot-nginx

# Obtain SSL certificate
sudo certbot --nginx -d your-domain.com -d api.your-domain.com

# Certificate auto-renews via systemd timer

Updating the application

# Connect to EC2
ssh -i your-key.pem ec2-user@YOUR_EC2_PUBLIC_IP
cd YOUR_REPO

# Pull latest changes
git pull origin main

# Rebuild and restart
npm install
npm run build
NODE_ENV=production npm run migration:run:prod
pm2 restart backend

✅ Code verification

Format code

# Automatic formatting of .ts files using Prettier.
npm run format

Lint code

# Check and automatically fix code style with ESLint.
npm run lint

Testing

# Runs tests: .spec.ts / .test.ts
npm run test

🛠️ Technology stack

• NestJS
• TypeScript
• Docker (local infrastructure only)
• PostgreSQL (AWS RDS in production, Docker locally)
• TypeORM
• Redis (Upstash in production, Docker locally)
• AWS S3
• Swagger
• OAuth2 / JWT
• Nodemailer