The catalog

Every area, every level. Filter from the top of the list, or just scroll.

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

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Intern
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0 / 6 areas

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

Foundations
Everyday engineering basics.
9 levels
  • Git Basics
  • The Terminal
  • HTTP Fundamentals
  • + 6 more
View all (9 levels)
Programming
The shape of code — language-agnostic fundamentals.
9 levels
  • Variables & Assignment
  • Control Flow
  • Functions
  • + 6 more
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Unix
The system around the shell.
9 levels
  • PATH & Environment
  • Processes & Signals
  • Permissions & Ownership
  • + 6 more
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Git
Version control, for real this time.
9 levels
  • Workflow
  • History
  • Collaboration
  • + 6 more
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Networking
How packets become pages.
9 levels
  • The Layered Model
  • DNS
  • TCP
  • + 6 more
View all (9 levels)
APIs
HTTP, REST, auth, pagination — the interfaces between services.
9 levels
  • HTTP Methods Deep Dive
  • Status Codes
  • API Auth Patterns
  • + 6 more
View all (9 levels)

Engineering craft

0 / 6 areas

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

Frontend
9 levels
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Databases
9 levels
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CI/CD
9 levels
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macOS
9 levels
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Languages

0 / 5 areas

Pick a language and learn its idioms end-to-end — types, control flow, the standard library, and the patterns the community has settled on.

Python
9 levels
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TypeScript
9 levels
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Bash & Zsh
9 levels
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Platforms & theory

0 / 8 areas

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

Containers
9 levels
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Cloud
9 levels
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Terraform
9 levels
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System Design
9 levels
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AI Systems
12 levels
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Languages & Runtimes
9 levels
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Algorithms
14 levels
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Data Types
9 levels
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Cryptography

0 / 6 areas

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

Encoding
9 levels
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Classical Ciphers
9 levels
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Modern Symmetric
9 levels
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Public Key
9 levels
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Hashing
9 levels
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Applied
9 levels
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Security practice

0 / 2 areas

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

Security Practice
9 levels
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Web Security
9 levels
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