---
title: 'Software Engineer at RunSybil'
canonical: 'https://feeny.ai/job/software-engineer-runsybil-new-york-m5jwav5bx9be'
type: 'job'
last_seen: '2026-09-10'
---

# Software Engineer at RunSybil

- **Company:** RunSybil
- **Location:** New York, NY
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2025-10-28
- **Last confirmed live:** 2026-09-10
- **Apply:** https://jobs.gem.com/runsybil/am9icG9zdDrIOH_dFtlxYdAnd6N7phsE

## Job description

## About RunSybil

RunSybil is an AI security startup scaling offensive security services by automating hacker intuition. We’re building Sybil: an AI-powered penetration testing product that finds vulnerabilities faster than human hackers. Backed by strong investor support and early customer traction, our team is composed of experts from the likes of OpenAI, Meta, Mandiant, Palantir, Cruise, and Trail of Bits.

## About this Role

We are seeking talented engineers intent on changing the security industry. If you have experience on fast-moving teams, scaling infrastructure with an eye towards reliability, and relentlessly optimizing: we want to talk to you.

What You’ll Do:

- Build secure, scalable systems for performing automated penetration testing at scale
- 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 Has A Mix of The Following:

- 6+ years of experience building products or platforms that serve real customers
- Strong understanding of distributed systems
- Has been a core contributor to scaling a product to meet increased demand
- Deep understanding of how to leverage modern AI for maximum impact
- Bonus: Built agents or agentic workflows
- Bonus: Relentlessly focused on the customer experience
- Bonus: Proficiency with cloud platforms (AWS, GCP, or Azure) and container orchestration
- 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.

What We Offer:

- Competitive Salary: Attractive startup compensation package with equity options
- Benefits: Excellent medical, dental, and vision plans. Unlimited PTO
- Growth Opportunities and Early Impact: Work directly with and learn from industry leaders while driving significant impact in our fast-growing security startup

We understand not every applicant will meet every qualification. We value hard work and potential, and still want to hear from you!

## About RunSybil

## Company Overview
- **One-liner**: RunSybil is an AI-native offensive security platform that autonomously discovers and exploits real-world vulnerabilities across modern applications, acting like an elite human researcher but at machine speed.
- **Entity Type**: Private (Seed stage – $40M raised)
- **Headquarters**: San Francisco, United States (with a hub in New York City)
- **Founded**: 2023
- **Founders**: Ari Herbert-Voss (CEO) and Vlad Ionescu (CTO)

## Core Business
- **Primary industry**: Computer and Network Security (AI-powered offensive security / automated penetration testing)
- **Target customers**: Enterprise security teams (B2B) – companies needing continuous application, cloud, and infrastructure security testing
- **Mission or purpose**: “Automate hacker intuition” – give every enterprise team the equivalent of a world-class red teamer that never sleeps

## Products & Services
- **[Sybil – AI Pentesting Platform]**: An AI-driven offensive security platform that continuously tests applications and infrastructure for exploitable vulnerabilities. It maps the entire stack (code, APIs, cloud, infra), reasons like an attacker, chains vulnerabilities across layers, and validates exploitability. Delivers findings on every pull request and re-evaluates with every deployment. Covers high-risk application testing, continuous attack surface monitoring, multi-tenant/business logic testing, bug bounty/pentest replacement, and cloud/infrastructure security validation. (Type: SaaS platform)

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private)
- **Key Metric**: Total Funding – $40M (Seed round, March 2026)
- **Notable Investors/Partners**: Led by Khosla Ventures (8 investors total). Team alumni include OpenAI, Meta, Mandiant, NCC Group, Trail of Bits.
- **Growth Signals**: LinkedIn followers grew +309.5% year-over-year (2,471 followers as of early 2026). Rapidly hiring across engineering, ML, and security roles. Product already delivering measurable improvements to security posture and development velocity for customers.

## Competitive Advantages
- **AI-native reasoning**: Sybil doesn’t rely on signature scanning – it dynamically interacts with systems, explores authentication boundaries, and chains vulnerabilities the way elite human attackers do, producing 90% fewer false positives.
- **Continuous, pre-validated findings**: Covers every deployment, not point-in-time pentests. Findings are validated as exploitable, eliminating triage burden.
- **Full-stack coverage**: Tests code, APIs, cloud, and infrastructure as an integrated system, finding attack paths that siloed scanners miss.
- **Founder expertise**: CEO was first security hire at OpenAI and contributed to GPT-3/Codex; CTO led offensive security at Meta and was core Llama offensive research lead. Combined AI research and elite red teaming background.

## Strategic Focus
- **Current priorities**: Scaling the platform to become the standard for continuous offensive security (CTEM Validation phase). Expanding coverage for multi-tenant and business logic testing. Building out the engineering and research team to accelerate product iteration.
- **Growth direction**: Replacing traditional bug bounty programs and periodic pentests with continuous, AI-driven testing. Enabling enterprises to move from reactive security to proactive, automated validation.

## Why Work Here
- **Culture**: Small, high-agility startup where “velocity and iteration” trump lengthy planning. Team of builders from OpenAI, Meta, Mandiant, and Trail of Bits. Emphasis on creative, hacker-like thinking – “our product automates hacker intuition.”
- **Remote/Hybrid Policy**: Hybrid with hubs in San Francisco and New York City. Remote or hybrid options available.
- **Benefits**:
  - Comprehensive insurance: Medical, dental, vision (100% employee, 80–85% dependents), travel insurance, pet insurance discounts.
  - Wellbeing: Mental health, coaching, fitness, primary care, healthcare navigation support, Employee Assistance Program.
  - Time off: Unlimited PTO (20-day suggested minimum), 14 company holidays, 12 weeks paid parental leave + flexible return.
  - Financial: 401(k) with 3% auto-enrollment, employee discounts, financial planning tools, commuter benefits.
  - Work & Culture: Company-provided laptop, regular team onsites/offsite, structured interview process that encourages LLM use.

## Sources
1. [runsybil.com/careers](https://www.runsybil.com/careers)
2. [runsybil.com/company](https://www.runsybil.com/company)
3. [runsybil.com](https://www.runsybil.com/)
4. [linkedin.com/company/runsybil](https://linkedin.com/company/runsybil)
5. [builtin.com/company/runsybil](https://builtin.com/company/runsybil)

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