Hugging Face Transformers

How LLMs work for Web Devs: GPT in 600 lines of Vanilla JS - Ishan Anand

Jul 13, 2025 · 1:41:34

Ishan Anand shows that GPT-2 small implemented in 600 lines of vanilla JavaScript makes LLMs understandable for web developers without ML backgrounds. He explains tokenization via byte-pair encoding, 768-dimensional embeddings representing semantic meaning via co-occurrence, and the Transformer's attention mechanism that lets tokens share context. The multi-layer perceptron learns next-token prediction through backpropagation, while the language head converts embeddings to token probabilities using softmax. Anand demonstrates each step—tokenization, embedding lookup, positional encoding, attention, MLP, and output—in a browser debugger, and notes that GPT-2's architecture underpins ChatGPT, with innovations like scale, supervised fine-tuning, and RLHF. The workshop provides an intuitive mental model of Transformers, turning perceived AI magic into understandable machinery.

Luminal - Search-Based Deep Learning Compilers - Joe Fioti

Jun 3, 2025 · 24:35

Joe Fioti presents Luminal, a search-based deep learning compiler that simplifies ML libraries to 12 primitive operations and uses search to automatically discover optimized kernels like flash attention. By representing models as directed acyclic graphs of these simple ops, Luminal keeps its codebase under 5,000 lines yet can run all major models. Its compiler applies 20-25 rewrite rules to search through equivalent GPU kernels, profiling to find the fastest—automatically rediscovering flash attention, an algorithm that took five years for the industry to develop. Data movement accounts for 99% of runtime, so kernel fusion merges many ops into one, dramatically speeding execution. An external auto-grad crate adds training support without altering the core. Future plans include supporting AMD, TPUs, and a serverless cloud that exports optimized graphs for inference.

Lessons from building GenAI based applications — Juan Peredo

Feb 22, 2025 · 33:13

Juan Peredo details the hidden complexities of building GenAI applications, from model hosting and cost control to output validation and observability. He compares local (Ollama) vs cloud hosting (Modal, SkyPilot) and warns that an agent processing 3,000 calls/day with OpenAI O1 costs nearly $300,000/month, while LLaMA 3.3 70B drops that to $50,000/month. He explains techniques to mitigate hallucinations—prompt engineering, guardrails, RAG, and fine-tuning—each with trade-offs like added latency or cost. Peredo advocates externalizing prompts via LangChain Hub for easy iteration and future-proofing, and illustrates agent design with parallel calls to reduce latency. Finally, he stresses observability using tools like LangSmith to debug probabilistic failures, such as an LLM failing on case sensitivity.