Design
URL Shortener (bit.ly)
Design a URL shortening service at massive scale — generating unique short codes, redirecting users, and providing analytics.
This is a Low-Level Design (LLD) problem. New to LLD vs HLD? Start here.
01 - Why interviewers ask this
It's the most popular "system design 101" question for a reason — interviewers use it to check ID-generation, redirect-latency, and read/write-scaling thinking, all in a small surface area.
02 - Where this system exists in the real world
You interact with this design every day.
bit.ly / TinyURL-style link shorteners
Marketing campaign link-tracking tools
QR code destination management
03 - What you'll master
Solve this once. Know it forever.
Generate unique short codes at scale
Optimize redirect read-path latency
Design click analytics without slowing redirects
04 - What you'll design
7 functional · 4 non-functional requirements.
Shorten a long URL to a 7-character unique code
6 more requirements inside
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05 - Companies that ask this
You may face this exact question in your next interview.
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See all requirements, use staged hints, run your code, and compare with community discussions - all on the same canvas.