Blog

Notes on learning, tools and engineering

Long-form explainers from the Coding Foding team, written so an intern and a senior both get something out of them.

• System DesignDatabasesScalingBackend

  ChatGPT Has a Billion Users. Where Does the Data Live?

  OpenAI's storage system, Habitat, handles 70 million requests a second across more than 500 PB of data. It started life as an ordinary Python library. Five engineering decisions worth learning from.

  November 1, 2026 · 10 min read · Read →

• AILLMProductivityTools

  The World of LLMs, in One Sitting

  There's a much bigger world beyond ChatGPT. From tokens and context windows to thinking models, deep research, Artifacts and your own AI agent, the whole picture in 20 steps.

  November 1, 2026 · 15 min read · Read →