The Design Patterns Nobody Told You About Agentic AI
Here's a confession: the first "agent" I built was basically a while loop with a prompt stapled to it. It called a function, read the result, and called another function. I thought I'd invented something. Turns out I'd just rediscovered ReAct, badly, three years after everyone else.
That's the funny thing about agentic AI right now. Underneath all the hype and the funding rounds and the "autonomous agent" landing pages, there are maybe seven recurring patterns doing all the real work. Once you can name them, you start seeing them everywhere: in LangChain's docs, in Claude Code's architecture, in that one open-source repo you starred and never opened again. Let's name them properly.
1. ReAct: think, act, look, repeat
This is the pattern everything else is built on top of. The model reasons about what it knows, picks a tool, fires it off, reads the result, and does it again. It's less "master plan" and more "detective walking around a crime scene picking up clues one at a time."
