Tom Yeh (@ProfTomYeh) / X

Tom Yeh

1,162 posts

Tom Yeh

@ProfTomYeh

CS Prof | AI by Hand ✍️ | @CUBoulder

Denver, CO

linkedin.com/in/tom-yeh/

Joined October 2009

Tom Yeh
@ProfTomYeh
Oct 11, 2025
At MIT, I learned about RNNs in my NLP class with Prof. Michael Collins. He built a model from my keystrokes to predict who I was. To me, it felt like a magic box. Years later, when I had to teach RNNs, I forced myself to go inside the box. ⬇️ Download: byhand.ai/rnn
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Tom Yeh
@ProfTomYeh
Jun 4, 2024
llm.c by Hand✍️ C programming + matrix multiplication by hand This combination is perhaps as low as we can get to explain how the Transformer works. Special thanks to @karpathy for encouraging early feedback and @7etsuo for helping me understand the pragma magic. I hope
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Tom Yeh
@ProfTomYeh
Oct 10, 2025
At MIT, the only course I ever dropped was signal processing. The DFT math was too intimidating. It’s so easy to just type fft() in MATLAB and move on. Years later, I finally did DFT by hand. ✍️ If you are also afraid of DFT, I hope this helps! ⬇️ Download:
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Tom Yeh
@ProfTomYeh
Sep 25, 2024
Recurrent Neural Network (RNN) by hand ✍️ Excel ~ I designed this exercise to practice calculating a small RNN by hand. I also made a medium and a large version to show how an RNN scales. 👇Join the 'AI Math' community. Download xlsx.
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Tom Yeh
@ProfTomYeh
May 26, 2024
Transformer by Hand✍️ To study the transformer architecture, it is like opening up the hood of a car and seeing all sorts of engine parts: embeddings, positional encoding, feed-forward network, attention weighting, self-attention, cross-attention, multi-head attention, layer
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Tom Yeh
@ProfTomYeh
May 28, 2024
SORA by Hand ✍️ OpenAI’s #SORA took over the Internet when it was announced earlier this year. The technology behind Sora is the Diffusion Transformer (DiT) developed by William Peebles and Shining Xie. How does DiT work? 𝗚𝗼𝗮𝗹: Generate a video conditioned by a text prompt
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Tom Yeh
@ProfTomYeh
Nov 6, 2025
Here's my beginner's lecture series for RAG, Vector Database, Agent, and Multi-Agents: Download slides: 👇 * RAG: byhand.ai/p/beginners-gu… * Agents: byhand.ai/p/beginners-gu… * Vector Database: byhand.ai/p/beginners-gu… * Multi-Agents: byhand.ai/p/beginners-gu… --- 100% original,
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Tom Yeh
@ProfTomYeh
Jan 29, 2025
DeepSeek lecture is edited and uploaded 👉 by-hand.ai/dpseek ~ Thank you all 🙏 for attending my public lecture yesterday. In one hour, I managed to build a simplified DeepSeek model in Excel in front of a live audience of 3000+ people.
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Tom Yeh
@ProfTomYeh
Nov 20, 2024
Transformer by hand ✍️ in Excel ~ I just released my first-ever "Full-Stack" implementation of the Transformer model. 👇Download xlsx to give it a try!
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3M
Tom Yeh
@ProfTomYeh
May 27, 2024
Vector Database by Hand ✍️ Vector databases are revolutionizing how we search and analyze complex data. They have become the backbone of Retrieval Augmented Generation (#RAG). How do vector databases work? [1] Given ↳ A dataset of three sentences, each has 3 words (or tokens)
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Tom Yeh
@ProfTomYeh
Feb 4, 2025
I edited and uploaded four videos to the RAG & AI Agents Playlist 👉byhand.ai/playlist
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Tom Yeh
@ProfTomYeh
Aug 25, 2024
Anna Rahn's video demonstration of Multi-Layer Perceptron (MLP) by hand ✍️ Anna made this short video for my computer vision course in the spring semester. Together with the spreadsheet exercise I posted yesterday, I hope they help more people understand deep neural networks!
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120K
Tom Yeh
@ProfTomYeh
Oct 18, 2025
Evolution of Deep Learning by Hand ✍️ As my tribute to Geoff Hinton's Nobel Prize, I drew this animation to illustrate the key idea behind Hinton's major contributions to deep learning over the years, with artistic liberty. ---- 100% original, made by hand ✍️ Join 40k readers
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Tom Yeh
@ProfTomYeh
Jan 26, 2025
I built a simplified DeepSeek model by hand ✍️ in Excel, for my lecture on Tuesday ~ Register 👉 by-hand.ai/dpseek
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