Fundamentals outlast tools
BuiltFromBits teaches the durable fundamentals of data and AI systems from the bit up, then proves them by shipping working code.
What BuiltFromBits is
Tools change every year. The layer below them changes every decade. A query planner still builds hash tables. A vector database still measures angles. An agent still calls functions and reads what comes back. Learn that layer once and the next tool is a weekend, not a reset.
So every topic here comes at you four ways, linked to each other: a lesson that explains it from below, a video that builds it, a conversation about it, and a problem you solve with real tests. Right now that's 4 tracks, 9 lessons and 40 practice problems, all open.
Who built it
I'm Ayan Putatunda. I'm a Staff Data Engineer working on AI platform work for a petabyte-scale Snowflake environment, with 13+ years in data engineering. I'm also a technical reviewer for Packt.
I built this because the most useful things I learned were never the tool of the year. They were the layer underneath: how bytes hit disk, why a join is fast, what an embedding really stores. This is where I teach that layer, and ship the code to prove it.
How it's made
The site is built in public. It's a static Astro site served from a CDN. Lessons, posts and problems are Markdown and YAML files in one Git repository, and every problem's reference solution is checked against its tests before it ships.
Your code runs in your browser. SQL runs on DuckDB-WASM and Python on Pyodide, each in a Web Worker. Nothing you type is sent to a server, which is also why running the site costs close to nothing.
I use AI tools in production: Claude Code helps write and refactor the site, check every practice problem's reference solution against its tests, and review content. I read and own every line that ships.
Everywhere BuiltFromBits lives
Contact
Email hello@builtfrombits.com, or message me on LinkedIn.