# Harness Engineering 101: The LLM Is the Brain, the Harness Is the Body

A Hacker News-linked article introduces “harness engineering,” arguing that an LLM is only the reasoning core while the surrounding harness—tools, memory, controls, and interfaces—determines what it can do. It matters because reliable AI systems depend as much on engineering around the model as on the model itself.

**Importance:** 2/5

## Sources

### Technology
- [Hacker News](https://github.com/IsuruMaduranga/harness-engineering-101) — Mon, 19 Oct 2026 12:07:41 +0000