Harness Engineer
Virio, San Francisco
The role
Location: San Francisco (in-person, in-office, full-time ONLY)
Compensation: $150K-$250K base + meaningful equity
What you will do
What you'll do
As a Harness Engineer, you'll own the intelligence layer that sits between our AI models and product: the system prompts, tool definitions, context management, and evaluation framework that makes agents actually work in production.
Specifically
- Build and refine the system prompts, tool integrations, and context windows that shape how our models behave across our platform, and you'll see how small prompt tweaks cascade into measurable product impact. (Nice to have: background in English, literature, creative writing, or humanities)
- Design the evaluation framework (LLM-as-judge evals, deterministic tests, production monitoring) that lets us ship with confidence. You'll define what success looks like and build the metrics to measure it.