System Design Interview: Design an E-commerce Checkout System
What Is an E-commerce Checkout System? The checkout system orchestrates the final steps of an online purchase: cart validation, inventory […]
System Design
← Tech Interview
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
System Design Interview: Design an Object Storage System (Amazon S3)
What Is an Object Storage System? Object storage (Amazon S3, Google Cloud Storage) stores arbitrary-size files (objects) in named buckets.
System Design
System Design Interview: Design a Social Graph (Friend Connections)
What Is a Social Graph? A social graph represents relationships between users: friendships (Facebook), follow relationships (Twitter/Instagram), professional connections (LinkedIn).
System Design
System Design Interview: Design a Payment Processing System
What Is a Payment Processing System? A payment processing system moves money from a buyer to a seller by orchestrating
System Design
System Design Interview: Design a Hotel / Booking Reservation System
What Is a Hotel Reservation System? A hotel reservation system lets users search for available rooms, make reservations with guaranteed
System Design
System Design Interview: Design a Key-Value Store (Redis / DynamoDB)
What Is a Distributed Key-Value Store? A key-value store maps arbitrary keys to values with O(1) average operations. Distributed key-value
System Design
System Design Interview: Design a Stock Exchange / Trading System
What Is a Stock Exchange System? A stock exchange matching engine pairs buy and sell orders in real time, executing
System Design
System Design Interview: Design Google Docs / Collaborative Editing
What Is Collaborative Document Editing? Real-time collaborative editing allows multiple users to simultaneously edit the same document, with changes from
System Design
System Design Interview: Design a Database Connection Pool
What Is a Database Connection Pool? Opening a database connection is expensive: TCP handshake, authentication, SSL negotiation, session setup —
System Design
System Design Interview: Design a Content Delivery Network (CDN)
What Is a CDN? A Content Delivery Network is a globally distributed network of edge servers (Points of Presence, PoPs)
System Design
System Design Interview: Design a Real-Time Bidding (RTB) System
What Is Real-Time Bidding? Real-Time Bidding (RTB) is the programmatic auction mechanism behind most digital display advertising. When a user
System Design
System Design Interview: Microservices and Service Mesh (Envoy, Istio, mTLS)
What Is a Service Mesh? A service mesh is an infrastructure layer that handles service-to-service communication in a microservices architecture.
System Design
System Design Interview: Design a Location-Based Services System (Yelp/Google Maps)
What Is a Location-Based Services System? A location-based services (LBS) system enables geospatial queries: find nearby restaurants, show points of
System Design
System Design Interview: Design a Task Scheduling System (Cron/Airflow)
What Is a Task Scheduling System? A task scheduling system triggers jobs at specified times or on recurring schedules. Examples:
System Design
System Design Interview: Design a Real-Time Chat Application (WhatsApp/Slack)
What Is a Real-Time Chat System? A real-time chat system enables persistent messaging between users with delivery guarantees and online