Build a Large Language Model (From Scratch) by Sebastian Raschka.

How to implement LLM attention mechanisms and GPT-style transformers.

In Build a Large Language Model (from Scratch) bestselling author Sebastian Raschka guides you step by step through creating your own LLM. Each stage is explained with clear text, diagrams, and examples. You’ll go from the initial design and creation, to pretraining on a general corpus, and on to fine-tuning for specific tasks.