System design interview questions

Practice system design interview questions. Each one is a structured walkthrough: requirements, data model, API, a high-level diagram, and deep-dive trade-offs.

4 questions

Design a URL Shortener

easy

Design a service like TinyURL or Bitly that turns long URLs into short, unique aliases and redirects users back to the original.

hashing
databases
caching

Design a Rate Limiter

Coming soon

Design a rate limiter that caps how many requests a client can make in a time window, with token bucket and sliding window strategies.

medium
algorithms
caching
distributed-systems

Design Pastebin

Coming soon

Design a service that lets users store and share text snippets with shareable links, expiration, and read-heavy access patterns.

easy
storage
databases
object-storage

Design Twitter

Coming soon

Design a social feed that supports posting tweets, following users, and building a low-latency home timeline at scale.

hard
fan-out
caching
feeds