Accessible with the Engineering pass and above.
Six months ago, building an agent meant writing a Python class with a `while` loop, tool definitions in dicts, manual state management or writing custom python functions. Today, you define an agent in a YAML file, drop a `SKILL.md` into a folder, and deploy. This talk traces the arc from "Agent in Python" to "Agent as filesystem". You'll learn the same agent built three ways: the hard way (Jan 2025), the simple way (Oct 2025), and the zero-code way (today).