--- title: 'Machine Learning Engineer at RunSybil' canonical: 'https://feeny.ai/job/machine-learning-engineer-runsybil-san-francisco-4gn81en20jpw' type: 'job' last_seen: '2026-09-08' --- # Machine Learning Engineer at RunSybil - **Company:** RunSybil - **Location:** San Francisco, CA / New York, NY - **Employment:** full-time - **Work type:** hybrid - **Posted:** 2026-03-09 - **Last confirmed live:** 2026-09-08 - **Apply:** https://jobs.ashbyhq.com/runsybil-jobs/9f668bdf-e5ed-4f7d-8300-117f1ccc2bab ## Job description ## About RunSybil Founded in 2023 by Ari Herbert-Voss and Vlad Ionescu, RunSybil is on a mission to automate hacker intuition. We’re building Sybil: an AI-driven pentester that discovers vulnerabilities before they’re exploited. As adversaries adopt AI to increase their attack surface, we’re putting cutting-edge offensive security into the hands of defenders. Backed by strong investor support and early customer traction, our team is composed of experts from OpenAI, Meta, Mandiant, Palantir, Cruise, Trail of Bits, and Aptiv. ## About this Role We are seeking talented engineers intent on changing the security industry. If you have experience on fast-moving teams and pushing out high quality experiments: we want to talk to you. What You'll Do: - Propose and implement technical initiatives based on product roadmap needs - Lead technical design discussions, contribute to team decisions, and provide feedback on engineering approaches - Translate ambiguous technical challenges into actionable plans, and execute them in collaboration with the team - Serve as the cornerstone of our engineering culture by setting and upholding exemplary standards for code quality, practices, and craftsmanship We’re looking for someone who brings: - Experience working with security data problems - MS or PhD in a quantitative discipline is nice but certainly not required - strong bias for building product-informing experiments versus published works - 4+ years of experience designing experiments and managing data infrastructure - Understanding of both modern and classic machine learning techniques - Equally comfortable with Jupyter notebooks and building data pipelines - Seeks autonomy, creative problem-solving, and moving quickly in an ambiguous environment Location: Hybrid role based in New York City. Some travel may be required. Diverse teams build better products. RunSybil is committed to hiring people who bring different perspectives, lived experiences, and backgrounds to our work. We encourage candidates of all races, ethnicities, gender identity and expression, sexual orientation, disability or medical conditions, ages, religions, and socioeconomic backgrounds to apply. Pursuant to the San Francisco Fair Chance Ordinance, we will consider for employment qualified applicants with arrest and conviction records. If you're excited about this role but don't check every box, we still want to hear from you. ## About RunSybil ## Core Business - **Primary industry**: Computer and Network Security / Offensive Security (AI-powered penetration testing) - **Target customers**: Enterprise B2B – security teams at high-risk, multi-tenant, or rapidly deploying organizations - **Mission**: “Automate hacker intuition” – replace periodic pentests and bug bounties with continuous, AI-driven validation of exploitable vulnerabilities. ## Products & Services - **Sybil Platform**: An AI agent that continuously tests applications and infrastructure by reasoning like an elite human attacker. It chains vulnerabilities across code, APIs, cloud, and infra to surface only real, exploitable paths. Deployed on every deployment, it provides feedback on pull requests and enables Continuous Threat Exposure Management (CTEM) validation. ## Market Standing - **Valuation/Market Cap**: Not disclosed - **Key Metric**: Total funding – $40M (Seed round, March 2026) - **Notable Investors/Partners**: Lead investor Khosla Ventures; 8 total investors in the seed round - **Growth Signals**: Headcount grew 185.7% YoY to ~10 employees; monthly LinkedIn follower growth of +8.0% and yearly +285.8%; recent $40M raise signals strong investor confidence. ## Competitive Advantages - **AI-native reasoning**: Sybil doesn't scan for signatures – it reasons like a human attacker, chaining multi-layer vulnerabilities and validating exploitability. - **Continuous, context-aware testing**: Re-evaluates the attack surface on every deployment, adapting to changes rather than running periodic generic checks. - **Reduced false positives**: Claims 90% fewer false positives by proving actual exploitability, eliminating triage burden. - **Team pedigree**: Founders and early team hail from OpenAI, Meta, Mandiant, NCC Group, and Trail of Bits – combining frontier AI research with elite red-team experience. ## Strategic Focus - Scaling the engineering and go-to-market teams to expand the platform’s coverage and customer adoption. - Replacing traditional bug bounties and point-in-time pentests with continuous, AI-driven offensive security. - Building a “company-survival mindset” and prioritizing velocity, shipping, and quality of thinking. ## Why Work Here - **Culture**: “Built by researchers. Driven by conviction.” Emphasis on shipping fast, thinking like an attacker, preempting what’s next, and engineering craft. - **Work model**: Hybrid with hubs in San Francisco and New York City; remote or hybrid options available. - **Benefits**: Comprehensive medical/dental/vision (100% employee, 80–85% dependents), unlimited PTO (20-day suggested minimum), 12 weeks paid parental leave, 401(k) with 3% auto-enrollment, mental health and wellness support, commuter benefits, company-provided laptop, regular team onsites. - **Team**: Small, high-caliber group (ex-OpenAI, Meta, Mandiant, NCC Group, Trail of Bits) working on the leading edge of AI and security. Interview process is structured, collaborative, and fast – LLM use encouraged. ## Sources 1. [runsybil.com](https://www.runsybil.com/) 2. [runsybil.com/company](https://www.runsybil.com/company) 3. [runsybil.com/careers](https://www.runsybil.com/careers) 4. [builtin.com](https://builtin.com/company/runsybil) 5. [linkedin.com](https://www.linkedin.com/company/runsybil) ## Other roles at RunSybil - [Security Analyst](https://feeny.ai/job/security-analyst-runsybil-united-states-g531z30tq8y7) — United States - [Software Engineer I](https://feeny.ai/job/software-engineer-i-runsybil-new-york-k0thqp47baj5) — New York, NY - [Forward Deployed Engineer](https://feeny.ai/job/forward-deployed-engineer-runsybil-united-states-z6x7c0j9xtj8) — United States - [Sales Development Manager](https://feeny.ai/job/sales-development-manager-runsybil-san-francisco-dwexshbs2sca) — San Francisco, CA - [Senior Account Executive, Technology](https://feeny.ai/job/senior-account-executive-technology-runsybil-san-francisco-ptqhwq1mrems) — San Francisco, CA - [Security Software Engineer](https://feeny.ai/job/security-software-engineer-runsybil-united-states-1pj8gsxey1nz) — United States - [Product Software Engineer](https://feeny.ai/job/product-software-engineer-runsybil-united-states-kdfnge6zpsev) — United States - [SRE/Infrastructure Engineer](https://feeny.ai/job/sre-infrastructure-engineer-runsybil-new-york-j7k1tddtxe0v) — New York, NY - [Machine Learning Engineer](https://feeny.ai/job/machine-learning-engineer-gatik-ai-santa-clara-qj4vvbdeqt4x) — Santa Clara, CA - [Machine Learning Engineer](https://feeny.ai/job/machine-learning-engineer-wynd-labs-remote-whe42v314npy)