LeetCode Prep
System Design FAQ
Design-interview Q&A by topic — fundamentals, data, distributed systems, cloud, and case patterns.
Frequently asked
System Design Q&A by topic
83 detailed answers across 8 topics.
Interview process
Formats, timing, estimation, whiteboard habits
Fundamentals
Scalability, latency, load balancing, availability
Caching & CDN
Cache policies, invalidation, CDN, stampede control
Data storage
SQL/NoSQL, sharding, replication, indexes, IDs
Distributed systems
CAP, hashing, consensus, queues, ordering
Cloud & ops
Multi-AZ/region, IAM, observability, cost
Case patterns
Feeds, chat, payments, booking, media, search
Career & leveling
Prep plans, seniority signals, common mistakes