Implementing LLM Architectures From Scratch
I shared a short talk on what I learned from implementing LLM architectures from scratch in Python and PyTorch.
The practical part is the workflow. When a new open-weight model comes out, I usually start from a compact reference implementation, trace the architecture changes, and compare those details against model cards, config files, and released code. This is often the fastest way to separate naming differences from actual design changes.
The talk is here: What I Learned From Implementing LLM Architectures From Scratch.
For related reading, see the recent LLM architecture developments article and the LLM Architecture Gallery.
Source: lightly edited website version of my Substack note.
Read Next
OpenAI Astra and Looped Transformers
A short note on OpenAI Astra, recurrent depth, looped transformers, Nanbeige 4.2, and the Mixture-of-Recursions paper.
Reasoning Models From Scratch: Code Setup
A short video on how conventional LLMs relate to reasoning models and agents, along with Python and PyTorch setup using uv.
Two Live Book Club Q&As on September 3
Two free live book club Q&A sessions on September 3 about Build a Reasoning Model From Scratch and related reader questions.
