The living reference for production AI systems

Learn AI system design,
the way it actually works.

Interview-ready depth on RAG, agents, inference, and evaluation — rewritten for clarity, built to go deep.

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foundations

How LLMs Actually Work

A ground-up tour of tokens, embeddings, attention, and why transformers scale.

retrieval

RAG Fundamentals

Why retrieval-augmented generation works, and how to build a pipeline that actually grounds answers.

agents

Agent Fundamentals

From single LLM calls to autonomous agents: planning, tool use, memory, and the control loop.