Software Engineer | AI Hacking Agents

Does the idea of building AI agents that push the limits of offensive cybersecurity gives you butterflies? Then look no further, and join us here at Hadrian as a Software Engineer focusing on building AI Hacking Agents !

Who Are We?

What if cybersecurity could think like a hacker? At Hadrian , that's exactly what we're building : the future of offensive cybersecurity, powered by autonomous AI agents that think like hackers . Founded in Amsterdam in 2021, we're on a mission to change the way organisations defend themselves by helping them find and fix security weaknesses before attackers can exploit them. Our platform brings together two products: Atlas , which continuously maps an organisation's external attack surface and validates which exposures are genuinely exploitable, and Nova , which uses AI agents to perform in-depth penetration testing on demand. Together, they give security teams the visibility and proof they need to focus on what really matters and stay ahead of emerging threats. Backed by $65M in total funding, including our recent $40M Series B led by Forgepoint Capital International and SmartFin, we're investing in the next generation of autonomous offensive security and expanding our impact across global markets. With a team spanning 25+ countries and offices in Amsterdam , London , and New York , we're helping organisations rethink what's possible in cybersecurity. Join us and help shape the future of offensive security.

Your Role

As a Software Engineer on Hadrian's AI team, you will help build and evolve our world-class AI hacker. You'll work on our agentic pentest product, as well as new AI-powered capabilities that push the boundaries of what automated hacking can do. We’re looking for someone who will take ownership of projects from ideation through development, release, and maintenance, working across everything from agent harnesses, software architecture, prompts and deployments. This is a role for engineers who enjoy getting close to the problem, moving quickly, and turning ideas into production-ready systems without unnecessary process getting in the way. You'll also be part of the team operating these systems in the real world! Your tasks will include evaluating pentests, investigating issues, and continuously improving the agents based on what you learn. If you're excited by the idea of combining strong software engineering with cutting-edge AI to build systems that can actually hack, we'd love to hear from you.

What You Will Do

• Build and optimize AI hacking agents that autonomously perform offensive security tasks and power Hadrian's agentic pentest product.
• Own projects end-to-end , from identifying an opportunity and designing a solution to shipping, operating, and iterating on it in production.
• Evaluate and optimize agent performance , using real-world pentest results and feedback to make our AI hackers more capable and reliable.
• Build high-quality, reliable, and debuggable software across LLM applications, agent harnesses, APIs, prompts, and data models .
• Respond to production issues and bugs, helping ensure our AI systems remain reliable as they operate against real-world targets.
• Move quickly from idea to MVP, learn from real-world feedback, and iterate until you have something that works.

You Are Fit for This Job Because You

• Are cracked at Python and have experience owning high-reliability Python codebases.
• Have hands-on experience building with LLM APIs .
• Have 3+ years of software engineering experience or equivalent experience building production software.
• Are comfortable taking end-to-end ownership of ambiguous and high-impact projects, including communicating with stakeholders outside of engineering.
• Are pragmatic and biased toward action. You ship a MVP quickly, learn from feedback, and improve it rather than waiting for perfection.
• Are excited to work 50%+ in person from our Amsterdam office.

Bonus Points If You Have

• Built AI agent harnesses or worked with agentic frameworks such as LangGraph, LangChain, or PydanticAI.
• Experience with TypeScript, Go, or C .
• Experience with Kubernetes, GCP, or AWS .
• Hands-on hacking or offensive security experience .
• Contributed significantly to open-source AI projects or repositories .
• Published research or presented at conferences in AI or related fields, alongside strong practical engineering experience.
• Experience building AI products at a startup or scale-up , or having founded a company yourself.

Benefits at Hadrian

• Permanent contract
• Unlimited paid holiday
• Stock options package
• Mobile phone stipend
• Work-from-home budget
• Business travel card
• Swapfiets
• Referral bonuses

Why You Want to Be Part of Hadrian

Make the internet safer: We enable companies to protect their customers, employees, and other stakeholders from malicious hackers by providing real-time Exposure Management from the Hacker’s perspective Board a primed rocket ship: Hadrian is growing fast; the team is approaching 100 wonderful people, notable customers are signed, and significant funding is raised. Now is the time to join our high-growth journey Be part of a strong and dynamic culture: Our values define who we are as a group and serve as the cornerstones to guide us in building a product that our customers love. At Hadrian, we achieve this by championing a culture that takes ownership, succeeds together, increases velocity, and pursues growth

Sounds like the role for you? Apply now! Our clients are seeking a world-class and reliable digital security service. That is exactly what we are offering. Therefore, a background check will be part of the process.