Free & open source

System design,
in depth.

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200: Topics
32: Simulators
15: Builds
470: Videos
600: Questions

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In every lesson

Intuition first

Hand-picked videos

Diagrams & notes

Audio narration

Check yourself

Code you can run

15 from-scratch builds

Layer 7 Load Balancer From Scratch Consistent Hashing Ring with Virtual Nodes Sliding Window Rate Limiter LRU Cache TTL Cache with a Redis-Style Adaptive Reaper Bloom Filter Membership Testing Snowflake 64-bit ID Generator Keyset (Cursor) Pagination vs SQL OFFSET Write-Ahead Log (WAL) & Crash Recovery LSM-Tree Key/Value Store Lease-Based Leader Election with Fencing Tokens Gossip: Push-Pull Anti-Entropy & SWIM Failure Detection Merkle-Tree Anti-Entropy Repair HyperLogLog Cardinality Sketch Tiny Search Engine

Curriculum

Fundamentals

01 Foundations 13 topics 02 APIs, services and protocols 13 topics 03 Data modeling and SQL 13 topics 04 NoSQL, partitioning and IDs 14 topics 05 Caching and fast reads 6 topics 06 Distributed coordination 13 topics 07 Storage engines 20 topics 08 Async work and streams 10 topics 09 Search and retrieval 17 topics 10 Analytics and sketches 13 topics 11 Realtime, social and feeds 10 topics 12 Geo, matching and recs 8 topics 13 Media, files and CDN 11 topics 14 Reliability and operations 13 topics

Real-world systems

15 Service and data designs 7 topics 16 Product designs 8 topics 17 Media and operations designs 6 topics

Case studies

18 Engineering case studies 5 topics

Start with the first lesson.

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