40 System Design Problems With Full 45-Minute Walkthroughs (Organized by Category)
The Only System Design Problem List You Need, Covering Forty Real Interview Questions Across Eight Categories With Full End-to-End Walkthroughs
If you are preparing for a system design interview, the fastest way to build real intuition is to study complete walkthroughs of the systems that actually get asked.
Below are 40 “Design X” problems, each with a full 45-minute breakdown, organized by the kind of system they represent.
Work through a few from each category and you will start seeing the same building blocks appear again and again. That pattern recognition is what carries you through any question, even one you have never seen before.
Social and Content
Design Instagram: https://designgurus.substack.com/p/how-to-design-instagram-in-45-mins
Design TikTok: https://designgurus.substack.com/p/system-design-interview-question-41e
Design LinkedIn: https://designgurus.substack.com/p/how-to-design-linkedin-in-45-mins
Design Twitter (weak vs strong answer): https://designgurus.substack.com/p/design-twitter-what-a-weak-answer
Design Facebook Newsfeed: https://designgurus.substack.com/p/designing-facebook-newsfeed-in-45
Design Reddit: https://designgurus.substack.com/p/how-to-design-reddit-in-45-mins
Design Pinterest: https://designgurus.substack.com/p/how-to-design-pinterest-in-45-mins
Design Notion: https://designgurus.substack.com/p/how-to-design-notion-an-all-in-one
Design Google Docs: https://designgurus.substack.com/p/how-to-design-google-docs-in-45-mins
Messaging and Real-time
Design WhatsApp: https://designgurus.substack.com/p/designing-whatsapp-in-45-minutes
Design Discord: https://designgurus.substack.com/p/system-design-interview-question-f9d
Design Slack: https://designgurus.substack.com/p/how-to-design-slack-in-45-mins
Design Zoom: https://designgurus.substack.com/p/design-zoom-in-45-mins-a-complete
Marketplaces and Booking
Design Uber: https://designgurus.substack.com/p/how-to-design-uber-in-45-mins
Design DoorDash: https://designgurus.substack.com/p/how-to-design-doordash-in-45-mins
Design Airbnb: https://designgurus.substack.com/p/design-airbnb-in-45-minutes-search
Design Ticketmaster: https://designgurus.substack.com/p/design-ticketmaster-ticket-booking
Design an E-commerce Platform: https://designgurus.substack.com/p/designing-an-e-commerce-platform
Storage and Media
Design Dropbox: https://designgurus.substack.com/p/system-design-interview-question-e46
Design YouTube: https://designgurus.substack.com/p/design-youtube-in-45-minutes-system
Design Netflix: https://designgurus.substack.com/p/system-design-interview-question-47c
Design Spotify: https://designgurus.substack.com/p/how-to-design-spotify-in-45-minutes
Design Twitch: https://designgurus.substack.com/p/how-to-design-twitch-in-45-mins
Design a Live Video Streaming Service: https://designgurus.substack.com/p/design-live-video-streaming-service
Design Amazon S3: https://designgurus.substack.com/p/system-design-interview-question-246
Search and Discovery
Design Google Search: https://designgurus.substack.com/p/how-to-design-google-search-in-45
Design Google Maps: https://designgurus.substack.com/p/how-to-design-google-maps-in-45-mins
Design an AI Recommendation System: https://designgurus.substack.com/p/system-design-case-study-how-to-design
Fintech and Trading
Design a Payment Gateway: https://designgurus.substack.com/p/the-system-design-behind-a-credit
Design Robinhood: https://designgurus.substack.com/p/how-to-design-robinhood-in-45-mins
AI Systems
Design ChatGPT: https://designgurus.substack.com/p/how-chatgpt-works-a-system-architecture
Design an AI Content Moderation System: https://designgurus.substack.com/p/system-design-case-study-how-to-design-7c1
Platform Building Blocks
Design a URL Shortener (Bitly): https://designgurus.substack.com/p/system-design-interview-question-f72
Design a Distributed Cache (Redis): https://designgurus.substack.com/p/system-design-interview-question
Design a Key-Value Store (DynamoDB): https://designgurus.substack.com/p/system-design-interview-question-566
Design a Notification System: https://designgurus.substack.com/p/system-design-case-study-how-to-design-75c
Design a Distributed Rate Limiter: https://designgurus.substack.com/p/design-a-distributed-rate-limiter
Design a Distributed Lock Service: https://designgurus.substack.com/p/how-to-design-a-distributed-lock
Design a Gaming Leaderboard: https://designgurus.substack.com/p/designing-real-time-leaderboards
Design a Metrics and Monitoring System (Datadog): https://designgurus.substack.com/p/design-a-metrics-and-monitoring-system
Bonus
Design a Unique Username Service: https://designgurus.substack.com/p/how-to-design-a-unique-username-service
If you read these in order within each category, you will notice the same patterns repeating: fan-out, sharding, caching, queues, and consistent hashing. That repetition is the real lesson.
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