Designing a URL Shortener in Javascript: Mastering System Design Interview Questions

Deeply Understanding and Answering System Design Interview Questions

Designing a URL shortener from a JavaScript (and possibly Node.js) perspective brings specific tools, libraries, and paradigms into focus. If you’re a senior JavaScript engineer, you’d not only be expected to understand the overall system design but also be adept at selecting and discussing the right JavaScript technologies for the job. Here’s a roadmap tailored for this profile:

Requirement Clarification

Start as usual by defining the problem:

• What’s the maximum number of URLs we expect to shorten?
• Do we need custom URLs?
• Any expected read/write ratio?
• Should the shortened URLs expire?

High-Level System Design

Briefly outline the main components:

• URL Encoder: For generating a short code for each URL.
• Data Store: To store the mapping between the shortened code and the original URL.
• Redirection Server: To handle redirection from the short URL to the original one.