FREE • OPEN SOURCE • LOCAL FIRST

Build the technologies
that built the world.

Understand the small ideas inside big systems. Write code, test your assumptions, introduce a failure, and repair it.

Choose your first lab ↗

10 executable labs0 paid dependencies1 language: JavaScript

YOUR LEARNING PATH

A world connected by ideas

Select a node to open its lab. Prerequisites appear below each node.

BUILD / BREAK / REPAIR

Choose something worth understanding.

Find a lab

DEPENDENCY FAILURE SIMULATOR

What survives when services fail?

A deterministic teaching model. It never contacts or disrupts a real service.

Disconnect dependencies

Recovery choices

Cache catalog locally Allow enrolled local users Queue draft orders

BUILT TO BE SHARED

Your next lesson could help someone else.

Contribute a test, a clearer explanation, a new lab, or an Assamese translation. The source archive includes contracts, reference solutions, contribution rules, and CI.