Tech stack:

• ExpressJS (Typescript)
• MongoDB

Approach:

Used incremental hash on short url generation. (1-9|a-z) (36^6 =~ 2 billion available)

Run the project

Using docker: docker pull jackere1/url-shortener docker run -p $PORT:$INTERNAL_PORT jackere1/url-shortener

With nodejs: npm install npm start

Usage

Shorten a URL GET: /shorten?originalURL=https://facebook.com => responds with { "shortURL": "123abc" }

Use shortURL GET: /:shortURL

Get visited counts of short url GET: /metrics/:shortURL

Project page url:

https://roadmap.sh/projects/url-shortening-service

Follow up:

When handling request, the request count in a short range of time can be very big. Implement a locking mechanism for the short URL index, otherwise the short URL collision will happen a lot during a spike.

Tips:

Use Database locking mechanisms for each request to achieve transactional operation. You can also use 3rd party software tools(Redis, MQ, Pub/sub etc) and services to make the request handling sequential.