From the first spark of ChatGPT to Claude Opus 4.7 — a backend engineer's field guide to the age of intelligent machines.
"The future is already here — it's just not evenly distributed." — William Gibson
📖 Start with the Preface — a short note on why this handbook exists and how to read it.
mindmap
root((The AI Saga))
Origins
AlexNet 2012
Transformers 2017
BERT vs GPT 2018
Scaling laws 2020
ChatGPT 2022
Concepts
Tokens + embeddings
Attention
RLHF
Context windows
Temperature
Patterns
Prompt engineering
RAG
Fine-tuning + LoRA
Tool use
Evals
Agents
ReAct loop
Multi-agent systems
MCP
Computer use
Practice
Coding assistants
Backend toolkit
Daily workflow
Cloud stacks
Career
Skills roadmap
Projects to build
Ethics + safety
Staying human
A working software engineer — maybe three to six years into a career — who is already fluent in Python or Java, lives in the web stack, and deploys to GCP or AWS. You are curious about AI, you've used ChatGPT and Copilot, and you suspect the ground is moving under your feet. You want:
This is written as a handbook for general use: linear if you want, skippable if you don't. Every chapter is standalone enough to read on a flight.
Each chapter ends with a Further reading & watching section. These links are the most important part of the handbook — the saga is still being written, and that's where you'll find the next month's updates.
timeline
title Fifteen years of the AI saga
2012 : AlexNet (deep learning works)
2014 : Seq2Seq + attention
2017 : Transformer paper
2018 : BERT / GPT-1
2020 : GPT-3, scaling laws
2022 : ChatGPT (Nov 30)
2023 : GPT-4, Claude, LLaMA, the agent boom
2024 : Computer use, MCP, reasoning models
2025 : Claude 4 family, GPT-5, Gemini 3
2026 : Opus 4.7, agentic coding as default
And the engineering worldview that follows from it:
flowchart LR
A[LLM] -->|+ memory| B[Chatbot]
B -->|+ retrieval| C[RAG system]
C -->|+ tools| D[Agent]
D -->|+ other agents| E[Multi-agent system]
E -->|+ standard interface| F[MCP-native platform]
F -->|+ autonomy + observability| G[Agentic software]
Every chapter in this handbook lives somewhere on that arrow.
Reading this handbook (about 12 hours) — linear path through the parts.
flowchart LR
subgraph p1["Part I · Origins"]
direction LR
a1[Prologue] --- a2[ChatGPT moment] --- a3[Anatomy of an LLM]
end
subgraph p2["Part II · Scaling"]
direction LR
b1[GPT-4 era] --- b2[Open source] --- b3[Prompt eng.] --- b4[RAG] --- b5[Fine-tuning]
end
subgraph p3["Part III · Agents"]
direction LR
c1["Chatbots → agents"] --- c2[Tool use] --- c3[Multi-agent] --- c4[MCP]
end
subgraph p4["Part IV · Claude"]
direction LR
d1[Opus timeline]
end
subgraph p5["Part V · Toolkit"]
direction LR
e1[Coding assistants] --- e2[Backend toolkit] --- e3[Stack-specific] --- e4[Workflows]
end
subgraph p6["Part VI · Road ahead"]
direction LR
f1[Skills roadmap] --- f2[Projects] --- f3[Ethics] --- f4[Epilogue]
end
p1 --> p2 --> p3 --> p4 --> p5 --> p6
flowchart TB
subgraph Foundations
T[Transformer] --> Pre[Pretraining]
Pre --> SFT[Supervised fine-tuning]
SFT --> RLHF[RLHF / Constitutional AI]
end
subgraph Capabilities
RLHF --> CW[Long context window]
RLHF --> MM[Multimodality]
RLHF --> RR[Reasoning mode]
end
subgraph Patterns
CW --> PE[Prompt engineering]
CW --> RAG[RAG]
RR --> COT[Chain of thought]
SFT --> FT[Fine-tuning / LoRA]
end
subgraph Systems
PE --> TC[Tool calling]
TC --> AG[Agent]
AG --> MA[Multi-agent]
MA --> MCP[MCP-native platform]
end
subgraph Product
MCP --> CO[Coding agents]
MCP --> CU[Computer use agents]
MCP --> DA[Domain agents]
end
This handbook distills decades of work by thousands of researchers and engineers across OpenAI, Anthropic, Google DeepMind, Meta FAIR, Mistral, the Hugging Face community, and countless universities and independent builders. It is opinionated where I think opinion helps, and quietly agnostic where it doesn't. Every claim about a specific product or model reflects the state of the world as of April 2026; expect anything vendor-specific to drift within weeks.
The AI Saga is versioned. Come back in a quarter and the later chapters will have moved. That's the point.
Ship something this week.