Leanpub Header

Skip to main content

LLM Engineering in Practice: Bridging Theory and Practical Application

LLM Engineering in Practice: Bridging Theory and Practical Application

The complete engineer's playbook for taking LLMs from theory to production — written by a practitioner who has done it at scale for over 60 million users. This book guides you through the entire LLM lifecycle — architecture, training, fine-tuning, deployment, RAG, and AI agents — with battle-tested techniques drawn from real industrial systems. If you want to stop prototyping and start building LLM-powered products that hold up in the real world, this is the guide you need.

Minimum price

$10.00

$14.00

You pay

Author earns

$

Also available for 1 book credit with a Reader Membership

PDF
EPUB
About

About

About the Book

In LLM Engineering in Practice: Bridging Theory and Practical Application, we take a comprehensive journey through the full lifecycle of large language models — from core architectural foundations to real-world intelligent system deployment. Whether you're an AI engineer looking to sharpen your production skills or a technical leader navigating enterprise LLM adoption, this book gives you the battle-tested roadmap you need. Authored by a practitioner with experience serving over 60 million users, every concept is grounded in real industrial-scale deployment.

The guide starts by laying the groundwork with a bottom-up overview of LLMs, exploring the core Transformer components and architectural decisions — including attention optimizations like GQA, MQA, and MLA, as well as Mixture-of-Experts and long-context modeling techniques — that separate research prototypes from production-grade systems.

As we progress, the guide walks you through the complete training pipeline. You'll master data preparation for pretraining, SFT, and RLHF, before diving into fine-tuning techniques ranging from full-parameter training to parameter-efficient methods like LoRA. Advanced reinforcement learning algorithms including PPO, DPO, GRPO, and DAPO are covered in depth, alongside multimodal training strategies that extend LLMs to images and video. The guide then transitions into deployment — covering quantization, pruning, and knowledge distillation — before culminating in two flagship application domains.

For intelligent RAG systems, you'll learn to build end-to-end retrieval pipelines spanning query understanding, index construction, hybrid recall combining BM25 and dense embeddings, re-ranking, and response generation — all designed for responsible, hallucination-aware production deployment.

For AI agents, you'll explore three agent frameworks — ReAct, Plan-Execute, and ReCode — alongside memory management, function calling, tool use, and a complete agent training pipeline from SFT initialization to reinforcement learning. You'll also tackle the real-world challenges of multi-agent coordination, safety, and ethical alignment.

This guide is designed to be hands-on, offering practical insights drawn from large-scale industrial deployments. Throughout, you'll build expertise with key tools including DeepSpeed, vLLM, VERL, Hugging Face Accelerate, and more. By the end, you'll have the skills and confidence to build, fine-tune, deploy, and scale LLM systems across real-world production environments.

Share this book

Author

About the Author

Contents

Table of Contents

CHAPTER 1: Introduction

  1. From Text to Generated Tokens
  2. Designing a New LLM: Core Factors
  3. Adapting LLMs to Business Requirements
  4. Reinforcement Learning
  5. Typical Industrial Applications of LLMs
  6. Summary

Chapter 2: Core Model Architectures

  1. Attention as a Tensor Operation
  2. Multi-Head Attention
  3. Transformer
  4. The distinction between encoder and decoder
  5. Analysis of Model Architectures
  6. The component optimization of Transformer
  7. Multi-Token Prediction(MTP)
  8. Summary

Chapter 3: Attention Mechanism Optimizations

  1. Multi-Head Attention (MHA)
  2. FlashAttention
  3. Multi-Query Attention (MQA)
  4. Grouped Query Attention (GQA)
  5. Multi-Head Latent Attention (MLA)
  6. Hybrid Attention: Integrating Gated DeltaNet and Gated SoftmaxAttention
  7. Summary

Chapter 4: Mixture-of-Experts (MoE) Architectures

  1. Principles of MoE
  2. Fine-Grained & Shared Experts in MoE
  3. Load Balancing in MoE
  4. Token-Dropping Strategy
  5. Summary

Chapter 5: Long-Context Position Scaling

  1. Conventional Positional Encoding
  2. RoPE: Rotary Position Embedding
  3. Direct Extrapolation (DE)
  4. Positional Interpolation (PI)
  5. NTK-Aware Interpolation
  6. NTK-by-parts Interpolation
  7. YaRN (Yet another RoPE extensioN)
  8. ReRoPE (Rectified Rotary Position Embedding)
  9. Summary

Chapter 6: Muon and MuonClip

  1. From AdamW to Muon
  2. MaxLogit Instability at Scale
  3. MuonClip
  4. Summary

Chapter 7: Preparing Data for Pretraining and Post-Training

  1. Pretraining Data
  2. SFT Data
  3. Data for Preference and Reward-Based Post-Training
  4. Summary

Chapter title

Chapter 9: Preference and Reward-Based Post-Training

  1. Proximal Policy Optimization (PPO)
  2. Direct Preference Optimization (DPO)
  3. Group Relative Policy Optimization (GRPO)
  4. GRPO-variants
  5. RL Tuning: Parameters, Strategies, and Issue Analysis
  6. Summary

Chapter 10: Multimodal Input and Vision Encoding

  1. Data Processing
  2. Model Calculation Process
  3. Vision Transformer (ViT) Encoder
  4. Window Attention
  5. Rotary Position Embeddings in Vision-Language Models
  6. Summary

Chapter 11: Systems for Distributed Training, Serving, and RL

  1. NCCL
  2. DeepSpeed
  3. vLLM
  4. Accelerate
  5. VERL: Training and Rollout Dataflow
  6. Summary

Chapter 12: Model compression

  1. Model Quantization
  2. Model Pruning
  3. Knowledge Distillation
  4. Summary

Chapter 13: Building Retrieval-Augmented Generation Systems

  1. Offline Indexing Pipeline
  2. Online Retrieval Pipeline
  3. Graph-Based RAG
  4. Governed RAG System
  5. Text-to-SQL
  6. Summary

Chapter 14: Building AI Agents

  1. The Orchestration Layer
  2. Tools
  3. Training Agents with SFT and RL
  4. Reliability and Safety
  5. Summary

Preface

Acknowledgements

The Leanpub 60 Day 100% Happiness Guarantee

Within 60 days of purchase you can get a 100% refund on any Leanpub purchase, in two clicks.

See full terms...

Earn $8 on a $10 Purchase, and $16 on a $20 Purchase

We pay 80% royalties on purchases of $7.99 or more, and 80% royalties minus a 50 cent flat fee on purchases between $0.99 and $7.98. You earn $8 on a $10 sale, and $16 on a $20 sale. So, if we sell 5000 non-refunded copies of your book for $20, you'll earn $80,000.

(Yes, some authors have already earned much more than that on Leanpub.)

In fact, authors have earned over $15 million writing, publishing and selling on Leanpub.

Learn more about writing on Leanpub

Free Updates. DRM Free.

If you buy a Leanpub book, you get free updates for as long as the author updates the book! Many authors use Leanpub to publish their books in-progress, while they are writing them. All readers get free updates, regardless of when they bought the book or how much they paid (including free).

Most Leanpub books are available in PDF (for computers) and EPUB (for phones, tablets and Kindle). The formats that a book includes are shown at the top right corner of this page.

Finally, Leanpub books don't have any DRM copy-protection nonsense, so you can easily read them on any supported device.

Learn more about Leanpub's ebook formats and where to read them

Write and Publish on Leanpub

You can use Leanpub to easily write, publish and sell in-progress and completed ebooks and online courses!

Leanpub is a powerful platform for serious authors, combining a simple, elegant writing and publishing workflow with a store focused on selling in-progress ebooks.

Leanpub is a magical typewriter for authors: just write in plain text, and to publish your ebook, just click a button. (Or, if you are producing your ebook your own way, you can even upload your own PDF and/or EPUB files and then publish with one click!) It really is that easy.

Learn more about writing on Leanpub