Easy
- Design URL Shortener like TinyURL
- Design Text Storage Service like Pastebin
- Design Leaderboard
- Design Content Delivery Network (CDN)
- Design Parking Garage
- Design Vending Machine
- Design Distributed Key-Value Store
- Design Distributed Cache
- Design Distributed Job Scheduler
- Design Authentication System
- Design Unified Payments Interface (UPI)
Medium
- Design Instagram
- Design Tinder
- Design WhatsApp
- Design Facebook
- Design Twitter
- Design Reddit
- Design Netflix
- Design Youtube
- Design Google Search
- Design E-commerce Store like Amazon
- Design Spotify
- Design TikTok
- Design Shopify
- Design Airbnb
- Design Autocomplete for Search Engines
- Design Rate Limiter
- Design Distributed Message Queue like Kafka
- Design Flight Booking System
- Design Online Code Editor
- Design Stock Exchange System
- Design an Analytics Platform (Metrics & Logging)
- Design Notification Service
- Design Payment System
- Design a Digital Wallet
Hard
- Design Location Based Service like Yelp
- Design Uber
- Design Food Delivery App like Doordash
- Design Google Docs
- Design Google Maps
- Design Zoom
- Design Distributed Counter
- Design File Sharing System like Dropbox
- Design Ticket Booking System like BookMyShow
- Design Distributed Web Crawler
- Design Code Deployment System
- Design Distributed Cloud Storage like S3
- Design Distributed Locking Service
- Design Slack
- Design Live Comments