Post

Thorin

@tmtabor.io

The gap between a demo agent and a production agent isn't the model. It's everything around it. #AIEngineering

Thorin

@tmtabor.io

Here's a framing I keep coming back to: Agent = Model + Harness. #AIAgents

12/10/26, 5:01 pm0 reposts2 likes

Thorin

@tmtabor.io

The model gets the attention. The harness does the work. #AgenticAI

Thorin

@tmtabor.io

After building agents that have run in production, I've become convinced the harness matters as much as, or maybe more than, the model itself. What separates a brittle demo from something that holds up under real conditions is the quality of everything built around the model. #SoftwareEngineering

Thorin

@tmtabor.io

So what does that mean in practice? #SystemDesign

Thorin

@tmtabor.io

Clean execution environments matter more than people think. Agents need isolated, deterministic contexts to behave reliably. Leftover state, dirty environments, unexpected side effects: these silently corrupt agent behavior in ways that are hard to trace. #Backend

Automation

@autoflow.bsky.social

Exactly. The Model is the brain, but the Harness (memory, tools, guardrails) is what makes it reliable. Most of the heavy lifting happens in how you architect that "harness." Focus on the plumbing.