https://nskillhub.com/categories/Classic/ Recent content in Classic on nSkillHub Hugo -- gohugo.io en © 2026 Lakshay Jawa Sat, 18 Apr 2026 23:28:29 +0530 https://nskillhub.com/system-design/classic/url-shortener/ Sat, 18 Apr 2026 00:00:00 +0000 https://nskillhub.com/system-design/classic/url-shortener/ <h2 class="relative group">1. Hook <div id="1-hook" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#1-hook" aria-label="Anchor">#</a> </span> </h2> <p>Every time you click a <code>bit.ly</code> or <code>t.co</code> link, a distributed system silently resolves a 7-character code to a full URL and redirects you — in under 10 milliseconds — before your browser even renders the loading spinner. Behind that invisible handshake sits a deceptively rich design problem: how do you build a service that creates billions of short codes, never loses a mapping, and serves hundreds of thousands of reads per second with single-digit millisecond latency, all while preventing abuse, surviving data-centre failures, and staying profitable?</p>