Module 5Transformer Deep Dive

Transformer Block Anatomy

Understand residuals, norms, and feed-forward layers as one optimization unit.

Why this module matters

Most transformer engineering is really about making deep residual stacks train reliably.

Prerequisites

  • Multi-head attention

Learning objectives

  • Explain pre-norm vs post-norm
  • Understand FFN width and capacity
  • Assemble a minimal block

Core concepts

Residual paths
LayerNorm placement
Feed-forward expansion

Hands-on practice

  • Build a transformer block and test on fake data

Expected output

A reusable transformer block implementation.

Study checklist

  • Explain pre-norm vs post-norm
  • Understand FFN width and capacity
  • Assemble a minimal block

Common mistakes

  • ⚠️ Wrong residual ordering
  • ⚠️ Ignoring normalization placement
  • ⚠️ Underestimating FFN compute

Module rhythm

  • 1. Read the summary and why-it-matters section first.
  • 2. Work through concepts before rushing into practice.
  • 3. Use the checklist to verify real understanding, not just completion.

How to continue

Next distinguish encoder and decoder reasoning patterns.

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How to use this page well

Treat each module as a compact learning system: understand the intuition, verify the concepts, do one hands-on task, then use the checklist and mistakes section to pressure-test your understanding.