Hey there, Cybersecurity Enthusiasts

At Factorial, we're on the hunt for a skilled Application Security Engineer to join our Security Team. We need your expertise to proactively hunt for vulnerabilities and strengthen our defenses against cyber threats. If you have a passion for ethical hacking and want to make an impact in a dynamic tech environment, we'd love to hear from you

Ready to be part of the challenge?

About the team

Security at Factorial works side by side with Product and Engineering to help a fast-moving, AI-native company ship without losing control of risk. Our mission is to protect Factorial and our customers while making security a practical part of how software is designed, built, tested, and operated.

The work goes far beyond finding vulnerabilities: we test real product surfaces, help teams fix issues properly, and turn repeated security needs into guardrails, automation, and CI/CD controls that developers can use every day. AI is part of Factorial’s culture, product, and way of working from day one, so Security also helps define how teams use agents, LLMs,



tools, and company data safely at scale, while actively challenging those systems with an attacker mindset.

It’s a team for people who want to keep learning, move across different security problems, and build security that can keep up with the speed of the company.

What You’ll be doing?

Perform proactive penetration testing across Factorial’s applications, APIs, infrastructure, and AI-powered features.

Reproduce and validate vulnerability reports submitted by third parties, like our bug bounty program.

Collaborate with development teams to remediate security findings and enhance secure coding practices.

Improve how we validate, triage, and remediate vulnerabilities from bug bounty reports, internal testing, automated controls, and external research.

Hunt for recurring or legacy vulnerability patterns based on root cause analysis, previous incidents, and security findings.

Build an

📌 Offensive Security Engineer (Barcelona)
🏢 Factorial
📍 Barcelona