I Visualized a Decoder-Only Transformer

I traced a single token through a decoder-only Transformer—end to end—so you can finally “see” what happens inside an LLM when it generates the next token. We follow one token from tokenization → embeddings + positional info → LayerNorm → multi-head self-attention (Q/K/V, causal mask, softmax) → residual connections → MLP → logits → sampling, and then show how KV cache speeds up the next step of generation. If you’ve ever wondered how ChatGPT picks the next token, this is the complete, visual walkthrough—every step, no hand-waving. transformer token journey one token decoder-only transforme…