Transformer Architecture - Chef & GPT Analogy
Transformer Step Chef & Bakery Procedure What GPT is Doing
1. Tokenization The chef prepares ingredients in separate bowls. "Eggs" in one bowl, "Flour" in another, "Butter" in a third. Breaking the sentence into pieces.
Example: ["Cat", "chases", "the", "mouse", "quickly"]
2. Embeddings Each bowl gets a detailed label that captures the ingredient's essence. The "Sugar" label describes it as sweet, granulated, and dissolvable. Turning each word into a number vector.
Example: "chases" becomes numbers representing "action," "speed," "movement," "predation."
3. Positional Encoding The chef notes the step sequence on the recipe. "Cream butter and sugar" must happen before "Add eggs". Remembering word order.
Example: Adding information that "chases" comes after "Cat" and before "the mouse."
4. Self-Attention Each ingredient searches for its most relevant partners. Butter looks around thinking: "I need to pay most attention to Sugar (to be creamed with) and Flour (to be mixed with)." Understanding which words connect.
Example: The word "chases" pays strong attention to "Cat" (who does the chasing) and "mouse" (what gets chased).
5. Multi-Head Attention Multiple specialised self-attentions happen simultaneously. One chef focuses on flavour partnerships, another on texture relationships; all ingredients are searching for different types of important connections at once. Analysing different relationships at once.
Example: For "chases":
• One head focuses on "Cat"→"chases" (subject-verb)
• Another on "chases"→"mouse" (verb-object)
• A third on "chases"→"quickly" (verb-adverb)
6. Feed-Forward Network Each ingredient gets individually refined and enhanced. The chef intensifies Vanilla's aroma, then balances it. Refining each word's meaning.
Example: Enhancing "quickly" to mean "high speed" and connecting it specifically to the action "chases."
7. Layer Normalization The process repeats through multiple layers - each with its own Multi-Head Attention and Feed-Forward steps. Stabilising the understanding before the next layer.
Example: Ensuring the relationship between "chases" and "mouse" remains clear as processing continues.
Layer 1: Mixing stage 1. Attention: "Butter checks its relationship with everyone: 'How much should I interact with Sugar? How much with Flour?'"
2. FFN: Butter actually gets whisked and blended with the (Flour and Sugar), transforming from a separate ingredient into part of a cohesive mixture.
Building deeper meaning.
Example: Now understanding that "chases" implies predation, speed, and that "Cat" is a predator while "mouse" is prey.
Layer 2: Baking Stage 1. Self-Attention: "The ingredients coordinate in the oven's heat: 'Which parts need to solidify first? Where should the air bubbles expand to make the cake rise evenly?'"
2. FFN: The actual chemical transformation happens: proteins in Eggs and Flour solidify into a firm structure, while air bubbles expand to make the cake light and fluffy.
Creating a coherent understanding.
Example: The entire phrase "chases the mouse quickly" is now a single event where action, target, and manner are fused into a complete concept.
8. Autoregressive Decoding The chef builds the final cupcake step-by-step. First, he bakes the cake (considering probabilities: 90% vanilla, 8% chocolate), then adds frosting (85% chocolate, 10% vanilla), then sprinkles (70% rainbow, 20% chocolate) - each step depending on the previous one. Generating the next word.
Example: After "Cat chases the mouse", it calculates: "quickly" (70%), "swiftly" (20%), "away" (10%), and picks "quickly".