---
title: 'Harness Engineer at Virio'
canonical: 'https://feeny.ai/job/harness-engineer-virio-san-francisco-j1vqa2xk522b'
type: 'job'
last_seen: '2026-09-08'
---

# Harness Engineer at Virio

- **Company:** Virio
- **Location:** San Francisco, CA
- **Compensation:** $150k–$250k
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-08-13
- **Last confirmed live:** 2026-09-08
- **Apply:** https://jobs.ashbyhq.com/virio/405b2e67-c75e-409e-8bbd-ae1c86b89eb4

## Job description

## HARNESS ENGINEER

Location: San Francisco (in-person, in-office, full-time ONLY)

Compensation: $150k-$250k base + top of market equity

## ABOUT VIRIO

Virio is solving an unsolved problem: how do you write perfect content? The best human strategist researches the space, finds the angle, and knows your goals and constraints — but they're capped by the hours in a day and one human career's worth of expertise. An agent isn't.

Crafting "perfect" content has three components:

1. Research: to identify and collect the best inputs
2. Synthesis: to devise the strategy and execute on it
3. Verification: RL verification of content quality and efficacy

We're backed by operators from LinkedIn, YouTube, HubSpot, Rippling, and Google. The team is almost 100% ex-founders and VCs from Yale, UC Berkeley, Stripe, and more. And we've consecutively added $1M ARR/mo because everyone and their co-founder wants what we're selling.

This problem doesn't have a playbook. We're looking for a Harness Engineer to obsess over AI-for-writing and own that layer end to end: the data feedback loop, evals, and harness design that turn a subjective judgment into something we can measure and improve — so day by day, we can get ever closer to solving content.

## 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—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.
- Architect the abstraction layer between our product (file systems, artifacts, skills) and the model's capabilities—making complex multi-step workflows feel natural to the model and reliable to users.
- Own prompt versioning, experimentation, and iteration. You'll A/B test prompt variations, measure their impact on agent quality, and ship improvements across our production system.
- Collaborate with product and engineering to identify signal—where our agents are failing, where users are stuck—and translate that into prompt and architecture improvements.

## WHAT SUCCESS LOOKS LIKE

- After 30 days: You understand our agent stack—the system prompts, available tools, context window strategy, and current failure modes. You've shipped your first prompt improvement and measured its impact.
- After 90 days: You've designed and implemented our core evaluation framework. Our team uses it as the source of truth for agent quality. You've shipped 2-3 meaningful prompt iterations that improved measurable outputs, and you're comfortable making architecture trade-offs.
- After 6 months: You own the harness layer end-to-end. You've architected improvements that reduced hallucination, improved context retention, or increased model reliability. You're driving architectural decisions about how we expose capabilities to the product team. You're writing technical content about how we've solved these problems—attracting the next generation of harness engineers to the company.

## TRAITS THAT THRIVE AT VIRIO

- High agency & self-direction – Acts without waiting for requirements or detailed instructions
- Small-team intensity comfort – Comfortable working intensely and closely with a small, high-output team
- Unorthodox problem solving – Sees non-obvious paths forward and challenges conventional approaches
- Quality-driven execution – Detail-oriented with high standards for correctness and quality
- Low ego & accountability – Takes full ownership and accountability for outcomes

## 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

This is a full-time, on-site role based in San Francisco. We do not offer hybrid or remote positions.

## About Virio

## Company Overview
- **One-liner**: Virio is an AI-powered B2B content marketing and lead generation platform that writes and publishes LinkedIn content for every employee at a company, turning executives into industry influencers and LinkedIn into a predictable GTM channel.
- **Entity Type**: Private (Startup)
- **Headquarters**: San Francisco, California, USA
- **Founded**: 2024
- **Founders**: Not publicly disclosed on the website or LinkedIn.

## Core Business
- **Primary industry/industries**: B2B Marketing Technology (MarTech), AI-driven Content Creation, Lead Generation
- **Target customers**: B2B companies, specifically vertical SaaS companies with high ACVs; Enterprise companies with large employee bases.
- **Mission or purpose statement**: To make every employee generate pipeline in their sleep by turning LinkedIn into the #1 revenue channel. The company's thesis is that "EGC is the new UGC" (Employee Generated Content is the new User Generated Content).

## Products & Services
- **Virio Platform**: An AI-powered content engine that combines "Agentic Deep Research" and "The Human Touch." The AI agent crafts posts about breaking news, ABM pipeline targets, and ICP topics. A human Content Engineer reviews and calibrates the GTM strategy weekly. After approval, Virio posts the content automatically on LinkedIn. The service targets specific ICPs and simulates reactions to optimize for engagement.
- **Content Engineering Service**: Virio pairs each client with a world-class content expert who learns the company's marketing initiatives and sales targets. This service is designed to replace or augment in-house content teams and agencies.

## Market Standing
- **Valuation**: Not publicly disclosed. The company is in a growth stage.
- **Key Metric**: The company reports generating **$110M+** in pipeline and **42M+** impressions for its clients. It has a headcount of **29 employees** (as of mid-2025) with a **+433.3% headcount growth year-over-year** and **+185.8% growth over the last 12 months**. [salaryguide.com](https://salaryguide.com/companies/virio), [linkedin.com](https://www.linkedin.com/company/virioai)
- **Notable Investors/Partners**: Backed by executives from **Notion, Rippling, and HubSpot**, as well as the biggest creators on LinkedIn. [virio.ai](https://virio.ai/)
- **Growth Signals**: The company has 13 active job postings (a **+160% quarterly increase**), indicating aggressive scaling. It has a strong focus on vertical SaaS, a market with high ACVs and few content voices, making it easy to dominate. [linkedin.com](https://www.linkedin.com/company/virioai)

## Competitive Advantages
- **Proprietary Data & Benchmarking**: Unlike in-house teams or ChatGPT, Virio benchmarks against thousands of posts and dozens of companies, learning what works in B2B content. It analyzes sales calls, pipeline data, and market benchmarks to engineer content.
- **Talent Density**: The company claims to pay **$500K+ packages** to elite operators who work in-person in San Francisco, creating a high-performance culture that agencies and in-house teams can't match.
- **Vertical SaaS Focus**: The platform is specifically optimized for vertical SaaS companies where there are few voices in the space, making it easy to become a trusted operator and close high-ACV deals.
- **Outcome-Based Model**: Virio guarantees a **3x ROI** and focuses on verifiable performance (targeting ABM accounts, simulating reactions, magnifying brand).

## Strategic Focus
- **Scaling the Go-To-Market Team**: The company is actively hiring for Enterprise Account Executives (Cybersecurity, Devtools/Data Infra), Founding Account Managers, and a Chief of Staff, signaling a push into enterprise sales and vertical expansion. [jobs.ashbyhq.com](https://jobs.ashbyhq.com/virio)
- **Product Development**: Building out the "AI marketer" to handle more complex content strategies and integrate deeper with LinkedIn's algorithm. The company believes LinkedIn is shifting from a recruiting platform to an ads platform, creating a massive opportunity for organic content.
- **Hiring for Scale**: Open roles for a Founding Recruiter, GTM Engineer, and Design Engineer suggest a focus on building the internal infrastructure to support hypergrowth.

## Why Work Here
- **Culture**: High-performance, in-person culture based in **San Francisco**. The company emphasizes working "around the clock" with elite operators. The environment is described as intense and results-driven.
- **Remote/Hybrid Policy**: **On-Site**. All employees work from the San Francisco physical office. [builtin.com](https://builtin.com/company/virio)
- **Compensation**: Very high compensation packages, with roles like Head of Content and Head of GTM paying **$280K - $520K** base salary, and roles like Founding Growth paying **$140K - $260K**. [salaryguide.com](https://salaryguide.com/companies/virio)
- **Notable Perks**: Working directly with top-tier B2B talent and creators. Opportunity to be a founding member of a rapidly growing startup backed by leaders from Notion, Rippling, and HubSpot.
- **Engineering Culture**: The company is looking for a "Founding GTM Engineer" and "Design Engineer," suggesting a tight-knit engineering team that builds directly for the GTM motion. The tech stack includes React, Webflow, HubSpot, LinkedIn Sales Navigator, and Figma. [linkedin.com](https://www.linkedin.com/company/virioai)

## Sources
1. [virio.ai](https://virio.ai/)
2. [linkedin.com](https://www.linkedin.com/company/virioai)
3. [jobs.ashbyhq.com](https://jobs.ashbyhq.com/virio)
4. [builtin.com](https://builtin.com/company/virio)
5. [salaryguide.com](https://salaryguide.com/companies/virio)

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