See inside how things work.

Real systems, algorithms and models, each as a live diagram you can break and fix. The diagrams are interactive and need JavaScript; these pages list everything there is.

Concepts: every idea on one page, with the diagrams that teach it.
Systems: a video platform, cut away, with live traffic.
Designing Data-Intensive Applications
System Design Interview
Introduction to Algorithms
Build a Large Language Model (From Scratch)
Operating System Concepts

An independent learning aid. Every explanation and drawing here is original; nothing is copied from the books. Not affiliated with any author, publisher or company named on this site.