Ultimate SDAI System Design
AI Powered Practice
Free, in-depth walkthroughs of the classic interview questions — with the interactive simulations embedded right in the guide. Don't just read about distributed systems. Break them. Fix them. Optimize them.
Step-by-step guide to the TinyURL system design interview question: requirements, capacity estimation, base62 encoding, database schema, caching, and the trade-offs interviewers probe. Includes an interactive encoding simulator.
How to design WhatsApp in a system design interview: WebSocket gateways, message delivery and ordering, offline storage, group fan-out, and end-to-end encryption — with interactive simulations of the hard parts.
Design a Redis-like distributed cache for a system design interview: LRU eviction, consistent hashing, replication, cache stampedes and hot keys — with interactive simulations of eviction and consistent hashing.
Step-by-step guide to the rate limiter system design interview question: requirements, capacity estimation, the five limiting algorithms compared (token bucket vs sliding window), distributed rate limiting with Redis + Lua, and fail-open vs fail-closed. Includes an interactive algorithm simulator.
Step-by-step guide to the Dropbox / Google Drive system design interview question: requirements, capacity estimation, chunking and deduplication, delta sync, metadata schema, conflict handling, and blob storage at scale. Includes an interactive chunking demo.
Step-by-step guide to the "Design YouTube" system design interview question: requirements, capacity estimation, resumable uploads, the transcoding pipeline, adaptive bitrate streaming (HLS/DASH), CDN delivery, and view counting at scale. Includes an interactive ABR simulator.
Step-by-step guide to the parking lot system design interview question: requirements, entity model, concurrent spot allocation across multiple gates without double-assignment, pricing and exit flow, and handling payment outages gracefully.
Step-by-step guide to the elevator system design interview question: requirements, the car state machine, SCAN/LOOK scheduling versus FCFS, multi-elevator dispatching, starvation avoidance, morning-rush handling, and fault tolerance.
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