System Design

Build systems that handle millions without breaking a sweat

5 posts

How MongoDB Works: A Visual Guide to Document Databases

Learn how MongoDB works from first principles. Interactive simulators for document storage, BSON structure, indexing, and the aggregation pipeline.

December 16, 202510 min read

System DesignDatabases

How PostgreSQL Works: Pages, Indexes, MVCC & WAL Explained

See PostgreSQL internals: 8KB pages, B-tree indexes, MVCC concurrency, and WAL durability. Interactive visual guide.

December 15, 202510 min read

System DesignDatabases

Database Sharding: Why Single Databases Fail at Scale

See why single databases fail at scale. Interactive guide to sharding strategies with Python implementation.

December 15, 202510 min read

System DesignDatabases

Database Replication: How Primary-Replica Keeps Data Safe

See why single databases fail. Interactive guide to primary-replica replication with Python implementation.

December 15, 202510 min read

System DesignDatabases

System Design Simulator: Build, Break, and Fix Databases

Interactive SimCity-style simulator where you build and break infrastructure. Add shards, replicas, and watch cascade failures teach you system design.

December 13, 202510 min read