System Design
Senior+Design scalable distributed systems. Critical for SDE-2 and above.
Overview
Key concepts
The framework
1. Clarify requirements (5 min) · 2. Estimate scale (5 min) · 3. High-level design (10 min) · 4. Deep dive (15 min) · 5. Trade-offs (5 min)
Common systems to practice
URL shortener · News feed · Ride-sharing · Distributed key-value store · S3-style object storage · Chat service · Search autocomplete
Key concepts
Horizontal vs vertical scaling · CAP theorem · SQL vs NoSQL · CDN · Load balancers · Consistent hashing · Rate limiting · Message queues
Question Bank
Practice questions
Common questions asked at Amazon for this topic. Check them off as you practice. Progress is saved in your browser.
Design a URL shortener like bit.ly. Handle 100M URLs and 10B redirects per day.
MediumDesign a social media news feed (like Twitter or Amazon's activity feed).
HardDesign Amazon's product recommendation system at scale.
HardDesign a distributed key-value store like DynamoDB.
HardDesign Amazon S3 — object storage at massive scale.
HardDesign a rate limiter for an API gateway.
MediumDesign a search autocomplete / typeahead system.
MediumDesign a notification system that supports email, push, and SMS at scale.
MediumDesign a distributed task/job scheduler (like AWS SQS + Lambda).
HardResources
Go deeper
Free, curated materials to supplement your prep.