Founding Security Software Engineer

Job Description

Job Description

Sage Recruiting's client is building the AI agent for hardware engineering. Software engineers got Cursor and Claude Code. The people who design cars, planes and rockets are next, and this team is building their version. Their customers will only let those agents work if they're provably secure, and that's where you come in.

Why this company

• The product works today. Their agent runs inside SolidWorks, CATIA, NX and Ansys and does real engineering work from plain-language requests.
• The traction is real. Revenue is in the seven figures and has doubled in six months. Fortune 100 automakers, aerospace companies and big tech are paying customers, and defense and other regulated buyers are next.
• The backing is serious. They've raised a $30M+ Series A from tier-one investors, including early backers of the leading AI labs. Joining before the next round means more equity.
• The bar is high. The founders are technical and have exited companies before. The CTO publishes in Nature and NeurIPS and is a Kaggle Grandmaster, and the tech leads come from Google and Meta.

The role

You'll be one of the company's first two security engineers and own its enterprise agent security from architecture to shipped code. The problem is largely unsolved: autonomous agents taking real actions inside native desktop software, on locked-down enterprise workstations, with some of the most valuable IP their customers have.

• Own the threat model and security roadmap, and make the calls on priorities and release readiness
• Secure agent execution on the desktop: sandboxing, scoped permissions, and approvals for consequential actions
• Harden the desktop app and its deployment: privileged integrations, packaging, signed updates, supply chain
• Build identity, credential and audit controls that pass security review at Fortune 100 and regulated customers
• Report directly to the CTO as a hands-on IC. You'll write production code every week

This is a builder role. Our client wants a strong software engineer first and a strong security thinker second, not a security analyst or compliance specialist.

Y

ou have

• 7+ years of engineering experience, working at a staff or principal level
• Rock-solid CS fundamentals: data structures, algorithms, concurrency, operating systems and systems design
• Security controls you personally built and shipped: authorization, secrets, process isolation, sandboxing or network boundaries
• Clear thinking about AI-specific threats like prompt injection, untrusted tool output and third-party extensions
• The judgment to lead an ambiguous roadmap and explain security guarantees clearly to engineers and customer CISOs

Bonus points: desktop or Electron app security, Windows or native sandboxing, AI agent runtimes or developer tools, enterprise identity, customer-hosted or air-gapped deployments, or CAD/CAE/PLM exposure.

The details

• Highly competitive cash compensation (up to $400K), plus meaningful equity
• San Francisco preferred, with fully remote considered for exceptional candidates who can work US hours. Visa sponsorship available
• A fast process: a Sage screen, fundamentals with the CTO, a 1-hour take-home on a real problem, and a half-day onsite. Offers can land the same day.