System Design Interview Guide
Everything you need to ace system design interviews: framework, common questions, case studies, cheat sheets, and practice problems.
📚 Articles (20)
System Design Cheat Sheets: Quick Reference for Every Key Concept
This is your one-stop quick reference for system design interviews. Every formula, number, pattern, and decision framework you need — condensed into scanna...
Common System Design Interview Questions: Top 20 with Approaches
This is your practical guide to the most frequently asked system design interview questions. For each question, you will find the problem scope, key requir...
Database Cheatsheet: SQL vs NoSQL, Indexing, Sharding, and Replication
Choosing the right database is one of the most consequential decisions in system design. This cheatsheet gives you quick-reference comparisons, decision fr...
Scalability Cheatsheet: Patterns, Numbers, and Formulas for System Design
This cheatsheet is your quick reference for all things scalability. From load estimation formulas to scaling patterns and capacity planning, everything you...
System Design Interview Guide: Framework, Time Management, and Expert Tips
The system design interview is the most impactful round in senior engineering interviews. Unlike coding interviews with clear right answers, system design ...
Design a Chat System
A real-time chat system supports 1:1 conversations, group chats, message ordering, offline delivery, and read receipts. Whether it is Slack, Discord, or a ...
Design Dropbox: A Cloud File Storage and Sync System
Dropbox synchronizes files across billions of devices, storing over 1 exabyte of data for 700+ million users. Designing a system like Dropbox tests your un...
Design an E-Commerce Platform
An e-commerce platform like Amazon handles hundreds of millions of products, processes millions of orders daily, and must provide a seamless shopping exper...
Design Google Search: A Web Search Engine
Google Search handles over 8.5 billion queries per day, indexing hundreds of billions of web pages and returning results in under 500 milliseconds. Designi...
Design Instagram: A Photo-Sharing Social Platform
Instagram serves over 2 billion monthly active users, handling photo uploads, news feed generation, stories, and social interactions at massive scale. This...
Design Netflix: A Video Streaming Architecture
Netflix serves over 260 million subscribers across 190+ countries, streaming billions of hours of content monthly. Its architecture is a masterclass in mic...
Design a News Feed System
A news feed is the core feature of most social media platforms — Facebook, Instagram, Twitter, and LinkedIn all depend on a well-designed feed. The news fe...
Design a Notification System
A notification system is a critical component of virtually every modern application. It delivers timely information to users through multiple channels — pu...
Design a Payment System
A payment system is one of the most critical components of any e-commerce or fintech platform. It handles money — making correctness, security, and reliabi...
Design a Ride Sharing System
A ride sharing system like Lyft or Ola connects riders with drivers using real-time geospatial matching. While similar to Uber (covered in a separate case ...
Design Twitter: A Social Media Microblogging Platform
Twitter (now X) processes hundreds of millions of tweets daily and serves billions of timeline reads. It is a classic system design interview question beca...
Design Uber: A Ride-Hailing Platform
Uber connects millions of riders with drivers in real-time across 10,000+ cities worldwide. Designing Uber is one of the most challenging system design pro...
Design a URL Shortener (like TinyURL / Bitly)
A URL shortener converts long URLs into compact, shareable links. This is one of the most commonly asked system design interview questions because it touch...
Design WhatsApp: A Real-Time Messaging System
WhatsApp is one of the most widely used messaging platforms, handling over 100 billion messages per day across 2+ billion users. Designing a system like Wh...
Design YouTube: A Video Streaming Platform
YouTube is the world's largest video-sharing platform, serving over 1 billion hours of video daily to 2+ billion users. Designing YouTube tests your knowle...
❓ Frequently Asked Questions
How do I prepare for system design interviews?
Follow a structured approach: learn fundamentals (CAP theorem, scaling, databases), study common patterns (caching, load balancing, queues), then practice with real case studies like designing Twitter or Netflix.
What framework should I use in a system design interview?
Use a 4-step framework: 1) Clarify requirements, 2) High-level design, 3) Deep dive into components, 4) Address bottlenecks and trade-offs. Always ask clarifying questions first.