Design Google Docs: Collaborative Editing and CRDTs
Design a real-time collaborative document editor like Google Docs. This is one of the most technically nuanced system design problems […]
System Design
System Design
Learn to design scalable, reliable systems that handle millions of users. System design interviews test your ability to architect real-world applications, considering tradeoffs, scalability, and best practices.
Core Topics:
Scalability: Load balancing, horizontal vs vertical scaling
Storage: Databases (SQL vs NoSQL), caching (Redis, Memcached)
Reliability: Replication, failover, disaster recovery
Performance: CDNs, caching strategies, database indexing
Common Design Questions:
Design URL shortener (bit.ly)
Design rate limiter
Design Twitter/Instagram feed
Design messaging system (WhatsApp)
Design file storage (Dropbox)
Interview Level: Senior engineers (L5+) at FAANG companies. Requires 3-5+ years experience to tackle effectively.
Preparation: Study system design patterns, understand distributed systems fundamentals, and practice mock interviews.
System Design
Design a Recommendation Engine (Netflix-style)
Design a recommendation engine like Netflix’s, Spotify’s Discover Weekly, or Amazon’s “Customers also bought.” Recommendation systems are one of the
System Design
Design an LLM Inference API
Design an LLM inference API — the service that accepts user prompts and returns model completions, like the OpenAI API,
System Design
Design a Monitoring and Alerting System
Design a monitoring and alerting system like Datadog, Prometheus + Grafana, or New Relic. This is a system design problem
System Design
Design an Ad Click Aggregation System
Design an ad click aggregation system — the infrastructure that counts how many times each ad was clicked, detects fraud,
System Design
Design a Stock Trading Platform
Design a stock trading platform like NYSE, Nasdaq, or a brokerage like Robinhood. This problem is notable for its extreme
System Design
Design a CDN (Content Delivery Network)
Design a Content Delivery Network like Cloudflare, Akamai, or AWS CloudFront. A CDN is infrastructure that most large-scale systems depend
System Design
Design a Distributed ID Generator (Snowflake)
Design a distributed ID generation service. Every large-scale system needs unique IDs — for database rows, events, messages, and transactions.
System Design
Design Google Maps / Navigation System
Design a navigation system like Google Maps. This problem combines geospatial data at scale, graph algorithms, real-time data ingestion, and
System Design
Design a Hotel / Airbnb Reservation System
Design a hotel or vacation rental reservation system like Booking.com or Airbnb. The core challenge isn’t the search UI —
System Design
Design a Proximity Service (Yelp / Nearby Search)
Design a proximity service like Yelp’s “restaurants near me” or Google Maps’ nearby search. The core challenge is geospatial indexing
System Design
Design a Payment System
Design a payment system like Stripe, PayPal, or an internal payments platform at a company like Uber or Amazon. This
System Design
Design a Distributed Key-Value Store
Design a distributed key-value store like DynamoDB, Cassandra (its KV layer), or Redis Cluster. This is one of the most
System Design
Design a News Feed (Facebook-style)
Design a news feed system like Facebook’s. This is a richer problem than the Twitter feed design — Facebook’s feed
System Design
Design a Web Crawler
Design a web crawler that can index a significant portion of the internet. This question tests whether you understand distributed