URL shortener

A simple URL shortener API running on NodeJS/Typescript/AWS Lambda/Serverless Framework/DynamoDB.

Original version (see branch) completed in a mad 3-hour dash for a coding exercise, tidied up later. The basic features are

• POST /?url={longUrl} endpoint for creating short URLS
  • returns short URL if given URL is already shortened
• GET /{shortUrl} endpoint that redirects to given target URL if found
  • we're keeping track of successful redirects for statistics
• GET /{shortUrl}/stats endpoint that returns hourly redirect counts per given shortUrl

Future work

• Use an async DynamoDB client to get rid of nested callbacks
• Write an OpenAPI schema and use API Gateway to validate requests
• Integration tests: try running integration tests locally against serverless-offline and serverless-dynamodb-local
• Smarter hourly time-series aggregation as opposed to the naive full-table scan
• CI/CD: build, run tests and lint on GitHub actions + run sls deploy if on master branch
• Set DynamoDB table names as Serverless Framework config variables and pass to Lambda handlers as env vars to avoid hardcoding table names to code
• Tune the Lambda IAM policy to avoid overly wide permissions

Dependencies

• yarn
• Serverless framework
• Java Runtime Engine (JRE) version 6.x or newer for local DynamoDB

Local development

First install dependencies:

yarn install
sls dynamodb install

Then start local development server with sls offline start.

Test

yarn test

Deploy

sls deploy