Microlearning
Twelve short lessons on LLMs, training, post-training, harnesses and the harness tax. Learn · See · Do · Quiz. Then the boss.
Tokens, guesses and the context window
Lesson 1
What's an LLM?
A very good next-word guesser
Lesson 2
Tokens & context
The model's units and its working memory
Lesson 3
Pre-training
The giant autocomplete in the library
From base model to assistant to reasoner
Lesson 4
Fine-tuning (SFT)
Flashcard school for assistants
Lesson 5
RLHF & preferences
The treat and the buzzer
Lesson 6
RL with verifiers
The gym with an answer key
Everything around the model
Lesson 7
What's a harness?
The brain in a jar gets a body
Lesson 8
Tools & the loop
How an agent actually takes action
Lesson 9
Context engineering
Choosing what the model sees
What overhead costs, and how to pay less
Lesson 10
The harness tax
The 50-pound backpack
Lesson 11
Model–harness fit
Why some models feel at home in some tools
Lesson 12
Paying less tax
Trim, cache, measure
15 questions · 70% to pass
Finish all 12 lessons to unlock
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