Build a Large Language Model from Scratch: The Complete Engineering Playbook
Building a GPT-style large language model yourself is the fastest way to stop treating foundation models as black boxes. This playbook walks through the full path used in educational GPT implementations: prepare text, implement attention, assemble a decoder-only stack, pretrain (or load weights), then fine-tune for classification or instruction following.
The conceptual sequence mirrors production LLM development at smaller scale. You can run the educational path on a laptop; frontier training still needs datacenter compute. Use this article as an engineering map, then implement with LLMs-from-scratch and Sebastian Raschka’s Build a Large Language Model (From Scratch) (Manning).