🔗 URL Shortening Service (Python MVC & Base62 Encoding)

Spanish | English

A backend service for efficiently shortening links, designed using the MVC (Model-View-Controller) architectural pattern in Python, with support for HTTP redirects, metric tracking, and a custom Base62 encoding algorithm.

Developed as part of the backend challenge series at roadmap.sh.

---

✨ Main Features

• 🏛️ Clean MVC Architecture: Strict separation of layers between routes/APIs (main.py), business logic (controller.py), data layer (model.py), and SQL schema (schema.sql).

• 🔠 Base62 Encoding Algorithm: Efficient generation of short keys and unique identifiers by combining timestamps and alphanumeric characters.

• 📊 Analytics and Metrics: Automatic tracking of click count (click_count) and creation and last update timestamps.

• ↪️ HTTP 302 Redirect: Proper handling of the HTTP protocol to track access without forcing the browser's permanent cache.

• 🗄️ Data Persistence: Integration with SQL databases (SQLite/PostgreSQL) for secure URL mapping management.

---

📂 Project Architecture

├── main.py # Presentation layer and HTTP request/route handling
├── controller.py # Business logic and shortening algorithm (Base62)
├── model.py # Data access layer (Queries, Inserts, Updates)
├── init_database.py # Idempotent database initialization script
├── schema.sql # DDL schema with tables, indexes, and constraints
└── README.md # Project documentation

🛠️ Technologies Used

• Language: Python 3.x
• Design Pattern: MVC (Model-View-Controller)
• Database: SQL (SQLite / PostgreSQL)
• Algorithm: Custom Base62 Encoding

🚀 Installation and Use

Prerequisites

Python 3 must be installed on your system.

Steps

1. Clone the repository:

git clone https://github.com/Aki-new/URL-Shortening-Service.git
cd URL-Shortening-Service

2. Initialize the Database:

python init_database.py

3. Run the service:

python main.py

💡 Workflow

sequenceDiagram
autonumber
actor User
participant Main as main.py (API/Routes)
participant Ctrl as controller.py (Logic/Base62)
participant Model as model.py (Data Layer)
participant DB as SQL Database

User->>Main: Sends Long URL

Main->>Ctrl: Requests URL Shortening

Ctrl->>Ctrl: Generates a unique key (Base62)

Ctrl->>Model: Saves mapping (Long URL <-> Key)

Model->>DB: INSERT INTO urls

Main->>User: Returns Short URL

Note over User, DB: Redirection Process

User->>Main: Query Short URL (/abc12)

Main->>Model: Searches for original URL and increments clicks

Model->>DB: UPDATE click_count / SELECT original_url

Main->>User: HTTP 302 redirect to Original URL

Loading

📋 API Specification

1. Shorten a URL

• Endpoint: POST /shorten
• Content-Type: application/json

Body Request:

{
  "url": "https://example.com/",
  "shortCode": "example"
}

Note: ShortCode is optional; if not added, one is generated randomly.

Response: (201 Created)

{
  "id": 1,
  "url": "https://example.com/",
  "shortCode": "example",
  "createdAt": "2026-07-06T13:25:00Z",
  "updatedAt": "2026-07-06T13:25:00Z",
  "accessCount": 0
}

2. Redirecting a URL

• Endpoint: GET /yourShortCode
• Response: (302 Found) (Redirects the user directly to the destination URL).

3. Retrieve URL statistics

• Endpoint: GET /shorten/yourShortCode/stats
• Response: (200 OK)

{ 
  "id": 1, 
  "url": "https://example.com/", 
  "shortCode": "yourShortCode", 
  "createdAt": "2026-07-06T13:25:00Z", 
  "updatedAt": "2026-07-06T13:25:00Z", 
  "accessCount": 42
}

4. Update an existing shortened URL

• Endpoint: PUT /shorten/yourShortCode
• Content-Type: application/json

Body Request:

{ 
  "url": "https://www.linux.org/",
  "shortCode": "linux-web-site"
}

• Note: shortCode is optional if you don't want to modify it
• Response: (200 OK)

{
  "id": 1,
  "url": "https://www.linux.org/",
  "shortCode": "linux-web-site",
  "createdAt": "2026-07-06T13:25:00Z",
  "updatedAt": "2026-07-06T13:30:00Z",
  "accessCount": 22
}

5. Delete a shortened URL

• Endpoint: DELETE /shorten/yourShortCode
• Response: (204) No content