Hafedh Hichri

Hafedh Hichri, also known online as not-lain, is a Software Engineer at Feyn (previously called Chonkie) and a Hugging Face Fellow

He is passionate about making AI accessible through open-source contributions to libraries like transformers, unsloth, peft, .... He studied Computer Science at the National School of Electronics and Telecommunications of Sfax (ENET'Com).

Blogs

I write about machine learning, natural language processing, and open-source software mostly in HuggingFace. Here are some of my recent blog posts:

👁️ Visualizing How VLMs Work A deep dive into how VLMs aggregate and process data across modalities, co-authored with Ed Daniels.
🔭 KV Caching Explained: Optimizing Transformer Inference Efficiency A deep dive into the concept of KV caching in transformers, explaining its significance and providing practical examples.
🔍 Mastering Tensor Dimensions in Transformers A comprehensive guide to understanding tensor dimensions in transformers, with practical examples and tips for effective manipulation.
🚀 PyTorchModelHubMixin: Bridging the Gap for Custom AI Models on Hugging Face A detailed exploration of the PyTorchModelHubMixin class, showcasing its role in integrating custom AI models with the Hugging Face ecosystem.
🧠 RAG using huggingface tools A step-by-step guide to building a Retrieval-Augmented Generation (RAG) chatbot using Hugging Face tools, with practical examples and code snippets.
🚀 Image-based search engine A tutorial on creating an image-based search engine using Hugging Face tools, with practical examples and code snippets.

Most of my work comes in this field the form of contributions to other libraries. A couple of notable libraries I contributed to are:

Note: Currently working at this company and serving as their maintainer.

I also maintain a couple of libraries:

I also contributed to integrating several models with Hugging Face using PyTorchModelHubMixin, including:

On February 19, 2026, I shared my knowledge about Chonkie and Qdrant integration in discord [slides]
On February 11, 2026, I was invited to Data & Beyond to talk about RAG and different approaches in the field [slides]
On January 18, 2026, I gave a keynote at Vectors in Orbit about Chonkie
On October 16, 2025, I gave a speech at PyData about AI agents [slides]
On October 9th, 2025, I gave a talk at the Hugging Face server about Building how VLMs work [slides].
On June 13 to 15 2025, I was one of the judges at Artificial Intelligence National Summit V3 and I gave a talk about Chonkie [slides].
On April 27, 2025, I gave a talk at the Genesis Labs-INSAT about AI in Healthcare [slides].