welcome

In this book, I invite you to embark on an educational journey with me to learn how to build Large Language Models (LLMs) from the ground up. Together, we'll delve deep into the LLM training pipeline, starting from data loading and culminating in finetuning LLMs on custom datasets.

For many years, I've been deeply immersed in the world of deep learning, coding LLMs, and have found great joy in explaining complex concepts thoroughly. This book has been a long-standing idea in my mind, and I'm thrilled to finally have the opportunity to write it and share it with you. Those of you familiar with my work, especially from my blog, have likely seen glimpses of my approach to coding from scratch. This method has resonated well with many readers, and I hope it will be equally effective for you.

I've designed the book to emphasize hands-on learning, primarily using PyTorch and without relying on pre-existing libraries. With this approach, coupled with numerous figures and illustrations, I aim to provide you with a thorough understanding of how LLMs work, their limitations, and customization methods. Moreover, we'll explore commonly used workflows and paradigms in pretraining and fine-tuning LLMs, offering insights into their development and customization.