Learn by breaking things, then fixing them.

Interactive practice for engineers. Security, coding, ops, networking — every level has a lesson, a sandbox, a visualizer, and a challenge. Pick any cabinet to begin.

Welcome to the arcade

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Welcome to the arcade

Pick any cabinet to begin — or let us pick for you.

Pick a section

Start where you're least comfortable — each area is independent and self-contained.

Rank
Intern
0 XP
1284 XP to Junior

Start here

0 / 5 areas

Day-one engineering fundamentals. Pick any one — each is self-contained and assumes zero prior context.

Foundations
Everyday engineering basics.
4 levels
  • Git Basics
  • The Terminal
  • HTTP Fundamentals
  • + 1 more
View all (4 levels)
Unix
The system around the shell.
5 levels
  • PATH & Environment
  • Processes & Signals
  • Permissions & Ownership
  • + 2 more
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Git
Version control, for real this time.
4 levels
  • Workflow
  • History
  • Collaboration
  • + 1 more
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Networking
How packets become pages.
4 levels
  • The Layered Model
  • DNS
  • TCP
  • + 1 more
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APIs
HTTP, REST, auth, pagination — the interfaces between services.
4 levels
  • HTTP Methods Deep Dive
  • Status Codes
  • API Auth Patterns
  • + 1 more
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Engineering craft

0 / 6 areas

The day-to-day toolkit of shipping software — frontend, data, delivery pipelines, reliability, and admin.

Frontend
5 levels
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Databases
5 levels
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CI/CD
4 levels
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macOS
6 levels
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Platforms & theory

0 / 6 areas

Where code runs and the ideas under it — runtimes, containers, clouds, AI, algorithms, and data structures.

Containers
5 levels
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Cloud
5 levels
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AI Systems
12 levels
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Languages & Runtimes
5 levels
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Algorithms
14 levels
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Data Types
5 levels
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Cryptography

0 / 6 areas

From encoding basics through classical ciphers to modern AES/RSA/hashing and applied protocols.

Encoding
5 levels
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Classical Ciphers
4 levels
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Modern Symmetric
5 levels
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Public Key
1 level
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Hashing
5 levels
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Applied
5 levels
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Security practice

0 / 2 areas

Applied defense: password storage, password cracking, and the web attacker's playbook.

Security Practice
2 levels
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Web Security
3 levels
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