Serverless URL Shortener

A fully serverless, scalable, and cost-efficient URL shortener built using AWS Lambda, API Gateway, and DynamoDB — deployed via Terraform. The system allows users to generate and access shortened URLs, leveraging the performance and affordability of AWS's serverless ecosystem.

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Features

• Serverless Architecture: Utilizes AWS Lambda and API Gateway for seamless scaling and zero server maintenance.
• DynamoDB Storage: Fast, reliable, and cost-effective NoSQL database for storing original URLs and their shortened slugs.
• Two Lambda Endpoints:
  • POST /shorten: Accepts a URL and returns a shortened slug.
  • GET /{slug}: Redirects the user to the original URL.
• On-Demand Billing: Uses pay-per-request DynamoDB and Lambda, minimizing costs and often staying within the AWS free tier.
• IAM Least Privilege: Uses Terraform-managed roles and policies to follow the principle of least privilege.
• Infrastructure as Code: Fully reproducible and version-controlled deployment using Terraform.
• Clean Teardown: All infrastructure can be destroyed using a single Terraform command.

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Tech Stack

Category	Tools Used
Cloud Provider	AWS
Compute	AWS Lambda
API Gateway	Amazon API Gateway (HTTP API v2)
Database	Amazon DynamoDB
Infrastructure	Terraform
Language	Python (with Boto3)

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Setup and Deployment

1. Prerequisites

• AWS CLI installed and configured (aws configure)
• Terraform installed
• Python 3.x installed

2. Configure AWS Credentials

aws configure
# Provide AWS Access Key ID, Secret Access Key, Region

3. Package Lambda Functions

cd scripts
bash deploy.sh

4. Deploy the Infrastructure

cd terraform
terraform init
terraform apply

Type yes when prompted to confirm infrastructure provisioning.

Terraform Init Screenshot

Terraform Apply Screenshots

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API Endpoints

After deployment, Terraform will output an API Gateway endpoint:

api_endpoint = "https://<your-id>.execute-api.us-east-1.amazonaws.com"

Shorten a URL

curl -X POST https://<api_id>.execute-api.<region>.amazonaws.com/shorten \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com"}'

Response:

{
  "short_url": "https://<api_id>.execute-api.<region>.amazonaws.com/a1b2c3"
}

Redirect to Original URL

curl -v https://<api_id>.execute-api.<region>.amazonaws.com/a1b2c3

Or open the shortened URL in a web browser.

Browser Redirect Screenshot

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API Routes

The application exposes the following HTTP API routes via Amazon API Gateway:

Method	Route	Description
POST	/shorten	Accepts a long URL and returns a shortened slug.
GET	/{slug}	Redirects the user to the original long URL.

API Gateway Console Screenshot

Below is a screenshot of the deployed routes as seen in the AWS API Gateway console:

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AWS Resources

Lambda Functions

• shorten_url.py: Generates short slugs and writes the mapping to DynamoDB.
• redirect_url.py: Retrieves the original URL from DynamoDB and returns a redirect response.

Lambda Console Screenshot

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DynamoDB Table

Stores mappings of slugs to original URLs. The table uses on-demand billing for cost efficiency.

DynamoDB Screenshot

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Teardown

To delete all infrastructure:

terraform destroy

Type yes when prompted to confirm.