Machine Learning Concepts

A four-level handbook from intuition to research and systems

Author

Lucas Sempé

Published

September 28, 2026

A four-level handbook

Machine learning, from first principles to deployed systems.

This handbook explains the mechanisms behind modern machine learning without asking readers to choose between intuition and technical precision. Each chapter develops one idea through explanation, mechanics, mathematics and code, and its consequences for research or production systems.

A way through a large field

The field is easier to follow when its dependencies are visible. The first part establishes how a model makes a prediction and how training changes its parameters. The next sections develop neural networks, representations and transformers before turning to large-language-model training, reasoning methods, multimodal architectures, deployment and responsible use.

Four levels, one argument

Every chapter begins with the question the concept solves. The same concept is then developed at progressively greater technical depth. Readers can stop at the level that matches their purpose or continue through the full sequence.

Level 1

Intuition

What the concept is, what problem it addresses, and what would fail without it.

Level 2

Mechanics

The steps, information flows and design choices that make the method work.

Level 3

Mathematics & code

The notation, objective functions and compact implementations behind the mechanism.

Level 4

Research & systems

What changes at scale, where evidence is limited, and how the method is used in practice.

What the book covers

Reference tool

Find a concept without losing its context.

The appendix collates the book’s core concepts and distinctions, with links back to the chapters where each one is developed.

Open the appendix

How to use the handbook

Read the chapters in order if the mechanisms are new to you: later chapters assume the conceptual sequence established earlier. If you already know the basics, use the table of contents to enter at the relevant part, then use the linked concepts appendix to recover any prerequisite. Code examples stay deliberately small. Their purpose is to expose the operation that a library would otherwise hide.