Founding Harness Engineer
About The Position
Virio is building the content engine for AI-native executives, focusing on ensuring AI output is trustworthy, reliable, and repeatable. The company emphasizes the importance of the 'harness' around AI models, including orchestration, evaluations, guardrails, and agentic scaffolding. Virio is backed by experienced operators from major tech companies and has achieved significant revenue growth. They are seeking a Harness Engineer to own the end-to-end development of systems that measure, constrain, and improve AI model outputs, ensuring quality scales with the company's growth.
Requirements
- High agency and self-direction
- Comfortable working intensely and closely with a small, high-output team
- Ability to see non-obvious paths forward and challenge conventional approaches
- Detail-oriented with high standards for correctness and quality
- Takes full ownership and accountability for outcomes
Nice To Haves
- Background in English, literature, creative writing, or humanities
Responsibilities
- Build and refine system prompts, tool integrations, and context windows to shape AI model behavior across the platform.
- Design the evaluation framework, including LLM-as-judge evaluations, deterministic tests, and production monitoring, to ensure confident shipping.
- Architect the abstraction layer between the product (file systems, artifacts, skills) and the model's capabilities for natural and reliable multi-step workflows.
- Own prompt versioning, experimentation, and iteration, including A/B testing prompt variations and measuring their impact.
- Collaborate with product and engineering to identify agent failure points and user friction, translating these into prompt and architecture improvements.
- Write technical content about solved problems to attract future harness engineers.
Benefits
- Work directly with the founders
- Competitive total compensation aligned to impact and ownership
- Meaningful equity upside as part of the founding team
- Medical, dental, and vision insurance
- 401(k) plan
- All working meals covered
- Relocation support for San Francisco
- Company-wide annual off-site
- High ownership, high trust, and fast career progression alongside world-class client partners
- In-person culture with deep commitment to excellence
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What This Job Offers
Job Type
Full-time
Career Level
Entry Level
Education Level
No Education Listed
